text:
PHP Programming/html output

There are a few different way you can display HTML using PHP. Generally, you will use the echo command to output something. This will be seen by a web browser, and then it will format it.

Breaking PHP for Output
In addition to using functions such as echo and print, you can also end your script, and anything beyond the end of the script will be output as normal HTML to the browser. You can also restart your script whenever you want after you've closed the PHP tag. Confused? It's actually pretty simple.

Let's say you had a for loop to count up to five and output it.

While I would tend to use templates for larger pages that output a lot, we'll get to that later. Remember how all your PHP scripts start with  and end with  ? Those don't have to be the very start and end of your file. In fact, PHP handles ending and restarting scripting just like if everything between the  and   tags were inside of an echo statement.

Thus, you could do something like this:

This is actually a very common method of outputting variables in a script, especially if there is a lot of HTML surrounding the variables. As I said before, I personally rarely ever do this, as in my opinion, using echo for smaller scripts keeps your code cleaner (and I would use templates for larger ones). However, we want to cover most of the language here, so this is another method you could use.

title: PHP Programming/html output


text:
Talk:Visual Basic

How to use this talk page
Just a couple of suggestions: kwhitefoot 06:50:07, 2005-08-26 (UTC)
 * please sign everything with four tilde characters like this ~ so that it is easier to tell who says what to whom.
 * Please be as specific as possible when complaining that the book is inadequate so that effort can be better focussed,
 * consider putting placeholder chapter headings in the actual book. I watch the contents page and all the pages I edit so I'll see the placeholders and try to expand them,
 * If you just change the spelling of a few words or correct some grammar here and there please mark it as a minor edit.

Guidelines for contributors
--kwhitefoot 18:14, 22 October 2005 (UTC)
 * Please capitalize VB code as in the VB IDE.
 * Remember that the book is about programming in VB Classic not VB.Net.
 * Prefix the names of all images with Visual Basic Classic. Please fix any instances that fail to follow this 'rule'.
 * The book is laid out like a printed b ook, everything is at the same level except for main page.  If you follow the Next link in the navigation template you should visit all the pages in the same order as they are found in the table of contents.

To Do

 * Rework the contents page in Python style perhaps. kwhitefoot 13:34:41, 2005-09-04 (UTC)
 * Add previous, next and Up navigation to each page using the prognav template? kwhitefoot 13:34:41, 2005-09-04 (UTC)

Too much like an encyclopaedia articla
This seems more like a Wikipedia explaination than a wikibooks lesson. I came looking to learn something, but went away with a description. HELP! -Jeshii 03:34, 8 Jul 2004 (UTC)

Probably too late for you, but it is getting better. kwhitefoot 06:50:07, 2005-08-26 (UTC)

Reply Yeah.. It does look like a encyclopedic article rather than a book. But I'll try to add more examples to make it more tutorial-ish.EugeneH 20:42, 3 Jan 2005 (UTC) Okay. I'll probably add a new section in the future if I have time...

Added some
I added the getting started section, this is my first Wiki work, so I hope I didn't mess anything up.

Moving
I think the Data types should have their own chapter. Beginner programmers shouldn't need to know it right away, and in depth like that should be saved for later in the book. Maybe after Data I/O?

Beginner's book?
I think this book is way too hard for a beginner... They will soon lose interest. Maybe this book should have more on GUI(Graphical user interface), since that's what VB is mostly used for. If we really want to make this book an easy tutorial, a lot must be rewritten. At least the structure of the tutorial should look like something to this effect:

Introduction - what's the advantages and disadvantages of vb? (in layman's terms) VB is made to be very convenient and user-friendly. Tell them you can make a program in 5 minutes. What is event-driven programming? Give the reader some ideas about it. Take some screenshots. List some cool things VB is good at. i.e. games, applications with heavy GUI, APIs(you can use APIs to make beeping noise etc.)

Exercise 1: Hello world How to create,save and compile your first program in VB Using Print statement to print "hello world" extension: using message boxes, using input boxes to make hello world

Exercise 2: Make a calculator Tell them what they should know: Buttons, Click events, Variables (simple data types), Some built-in functions they need. After they're done, tell them what else they could add to make it better.

Exercise 3: Simple text editor Tell readers what they need to know: Components - learn about rich text boxes More about functions, subroutines How to improve

Exercise 4: First game Introduce: Keyboard events, pictureboxes, shapes, imageboxes, timer movement, game loop, random numbers(rnd and randomize),Types extension: music,winsock(for multiplayer games),classes(OOP)

Exercise 5: how to make an extremely annoying program more on APIs, GUI, ... ...

 * sigh* but you almost have to change everything...

its not impossibble
Thats where I was going with the getting started, learning how to print. This does need to cater more to beginners, however, the advanced content should stay. Just as learning anything goes, it should be progressively harder. If you want to extend the "getting started" area with some examples, go ahead. After giving the user an idea of the VB layout and uses, then they can get into the advanced of loops and such. Once I do some more I hope to make alot more reference programs, like the blast effect and such. I appreciate your contribution though, but maybe we should have some direction? Are you OK with you making the Beginners area more extensive, and I go on with Loops and Data and all the good stuff? Also, we should add programs to the end of each section, showing a common application of the learned technique.

okay I'll extend the beginner's sections. The "visual" part. I think we should have more of those since VB is made for rapid application development... But the fundamentals certainly can't be ignored.

Just some standards
I got rid of any mention of file numbers in I/O, just thought it was confusing, also never heard the use of file number before :P Replaced it with channel number instead. Just keep this in mind when adding more for the sake of the reader. Any ideas on other things to make standard, so we're not using a bunch of different terms to confuse the reader?

yes Yeah that's fine with me. I'll let you know in the future before changing any terms. I never heard of channels before either. But that makes it easier for the readers.

Another note we need to make a standard for picture box names. I feel "pic" works fine, so if its ok with you, ALWAYS use pic.print and what not.

hmmm pic is fine for a picture box, but when "Printing", it's easier to type "print" than "pic.print". :/ It just "prints" on the current Form instead of a picture box. So why don't we all use print?

nah I always thought that was sloppy and hard to read, pic.print is only 4 letters more :P

Random Numbers
Shouldn't the random numbers section mention "ranzomize"? -Joshtek (from other Wikipedia)

This may be rather basic, but shouldn't you tell them how to find/get a Visual Basic editor?

Credits and permissions
Not sure how material lifted from other works should be acknowledged but it seems a good idea to actually record any documentation regarding permissions.
 * This is now collected on Credits and Permissions. --kwhitefoot 17:44, 27 November 2005 (UTC)

GUI Computing Pty Ltd/Mark Trescowthick
Copy of email giving permission for use of coding standards and forum content.

Kevin,

In answer to both emails.

1. Copyright. All we would require is a general statement on the contents page, we certainly wouldn't wish the effort on you of somehow trying to keep track of AVDF content page by page... that would render it pretty much unusable I should have thought! A link to avdf.com would be nice if that doesn't cause any stress.

2. Licensing. Having reviewed your licensing arrangements, I can confirm that GUI Computing Pty Ltd, owner of all copyrights in the material contained both on avdf.com and in the GUI Coding standards, agrees for you to use our above referenced work under terms of the GNU Free Documentation License.

3. Contribution. Keep me in the loop as the project moves forward. I shall mention it to my developers at our next meeting... these days, of course, most of them are .NET hotshots who consider VB "legacy", but there are a couple who might be interested.

Finally, if you need anything in addition to the above, please yell.

All the best,

Mark

> -Original Message- > From: Kevin Whitefoot [mailto:kwhitefoot@hotmail.com] > Sent: Wednesday, 28 September 2005 4:31 AM > To: Mark Trescowthick > Cc: kwhitefoot@hotmail.com > Subject: RE: Visual Basic Classic WikiBook > >  > I've just skimmed the coding standards document. I think > that it would be > perfect addition. It is similar in many ways to the corporate coding > standards in force (though not enforced) at the company where > I work. I > can't use ours without rephrasing it completely because in such a big > company there is no one with the authority to allow it, > anyway, your's is > much better written. > > The Wikimedia project is a bit paranoid about copyrights and > so on so at > risk of sounding ridiculously finicky I think I should ask > for an explicit > statement from you that you are willing for the work to be > relicensed under > the GFDL. Here is an excerpt from the Wikibooks boilerplate > request for > permission > (http://en.wikibooks.org/wiki/Wikibooks:Boilerplate_request_fo > r_permission): > > =====quote > However, we can only use your materials if you are willing to grant > permission for us to use your above referenced work under > terms of the GNU > Free Documentation License. This means anybody will have the > right to share > your materials and update them: for example, to keep up with new > information. You can read this license in full at: > http://wikibooks.org/wiki/GNU_Free_Documentation_License > (note: To keep things simple, we don't use Invariant > Sections, Front-Cover  > Texts, or Back-Cover Texts) > > The license also expressly protects authors "from being considered  > responsible for modifications made by others" while ensuring > that authors > get credit for their work. There is more information on our > copyright policy > at: > http://wikibooks.org/wiki/Wikibooks:Copyrights > =====end quote > >  > Kevin Whitefoot > > ---

Elliot Spencer
From : 	Elliot Spencer  Sent : 	11 September 2005 13:48:26 To : 	"'Kevin Whitefoot'"  Subject : 	RE: VB tutorials You're welcome to use those bits from my site Kevin, I swapped over to DotNet as soon as it came out so I don't use vb6 anymore, haven't for quite some time. Sorry. Regards Elliot Spencer -Original Message- From: Kevin Whitefoot [mailto:kwhitefoot@hotmail.com] Sent: Saturday, September 10, 2005 7:51 PM To: elliotspencer@ilook.fsnet.co.uk Subject: VB tutorials I'm editing the Visual Basic book on WikiBooks (http://en.wikibooks.org/wiki/Programming:Visual_Basic_Classic) and I wonder if I might include some of your articles in it. Of course if you felt like contributing to the book yourself that would be even better. When I started adding to it I thought I would be one among many but it seems that VB6 programmers are a shy and retiring lot. Kevin Whitefoot. (http://en.wikibooks.org/wiki/User:Kwhitefoot)

Name is not descriptive of the contents
This wikibook would be better named Visual Basic 6 since that is the only version it talks about. There were five other versions of VB Classic for Windows and one for MS-DOS, so the contents of the book don't really live up to the title. The contents describe features which won't work in VBWin3 or earlier and both the 16-bit VB IDEs and the VBDOS IDE are completely different from the one described here. In order to make the book match the title you either need to add a lot more material on the different versions, or to change the title. A title change would be a lot less work.

Must admit that I like the content though. You've done a good job of describing VB6.

 * You sound like a level headed and knowledgeable person; how about lending a hand? Please at least create an account and sign your contributions with four tildes so that we can tell who says what :-)  I agree that the emphasis is on VB6 but most will work on VB5 and a lot on VB4.  As for VB3 and VB.DOS, I've never used them for more than the most trivial of tasks so i'm not really qualified.  If you could track down a tutorial on VB.DOS, VB3, etc. that is in the public domain ro get an author to relicense one then we could create several books.  --kwhitefoot 22:30, 3 October 2005 (UTC)

 * Are we going to rename this book? I think you would get more interest if the focus was narrowed to just VB6, especially if the title mentioned VB6. - Bevo 22:38, 23 October 2005 (UTC)

 * I renamed it Visual Basic Classic because it was originally just Visual Basic and I wanted to distinguish it from VB.NET. The name VB Classic seems to be quite common now but I think you have a good point because it is mostly used by those who are already expert users.  For now I'll add a redirect page that uses VB6 in the title.  You said we in your first sentence, I hope that means you intend to take part :-) --kwhitefoot 10:26, 24 October 2005 (UTC)

How do you search inside a Wikibook?
With all the substructure to this Wikibook, I'm having trouble figuring out how to do a search within it (all of it, not just the current page). - 65.119.52.66 19:37, 14 November 2005 (UTC)
 * If you can think of a better structure I'm open to suggestions. And if you ever find a way of confining a search to a specific book I'm sure a lot of people would love to know.  Probably best to discuss searching on this page: Wikibooks_talk:Searching  --kwhitefoot 20:13, 14 November 2005 (UTC)

 * Search normally would but include the book title. So to search for the history of Visual Basic Classic withing this book, search for "Programming:Visual Basic Classic/History".SteveSims 23:03, 23 June 2007 (UTC)

Visual Basic Classic suggested merge
User:Hagindaz has suggested that Programming:Visual Basic Classic should be merged with VB6 Command Reference? I think that a better course would be for the contributor to VB6 Command Reference to add to Programming:Visual Basic Classic but I might be biased. --kwhitefoot 13:54, 13 April 2006 (UTC)

 * I meant that VB6 Command Reference should either be added as an appendix to Programming:Visual Basic Classic, or have any useful content added to Programming:Visual Basic Classic, then redirected. I found VB6 Command Reference as an orphaned module. Since both books are on the same subject, so I don't think there is any reason to have them both exist as separate books. I'm sorry I wasn't clear, you can't add notes to merge. --Hagindaz 17:27, 13 April 2006 (UTC)

 * Thanks for the clarification. I wonder if we can change the merge template to allow for a short explanation?  Anyway I added a note to the talk page of the contributor, perhaps he or she will get in touch.  --kwhitefoot 20:44, 14 April 2006 (UTC)

 * I've just taken a look at the merge templates. In fact they do allow for optional reason to be added.  There are also mergeto and mergefrom templates that indicate which direction the content should move.  That was something I didn't know.  I'll try the exercise of changing the modules to add a reason for the merge.  --kwhitefoot 20:59, 14 April 2006 (UTC)

 * Merge completed. (There was an uncommented program that I deemed not usable and of no real importance) --Panic (talk) 07:06, 27 March 2010 (UTC)

Splitting into subpages
The book has originally been written as one page. It was split into subpages during August and September 2005 by. For one of the last revisions of the book in one page, see revision 211226. --Dan Polansky (discuss • contribs) 19:24, 7 September 2012 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Visual Basic


text:
User:Rosskurator~enwikibooks

I’m writing my thesis in media and communication studies at the University in Zurich (Switzerland) about Wikipedia. I research the following question: What are the conditions for a wiki system to produce journalistic texts of high quality. I measure the influence that traffic, number of edits, vandalism, anonymous edits and relevance have on the quality of the articles. To put it into concrete terms, I try to find answers to the following questions:

 * What is the critical mass for users and authors in a wiki system?
 * What effect have number of edits, authors and discussion edits, traffic, age of the article and backlins on quality?
 * what influence has vandalism on quality?
 * Do anonymous authors contribute in a positive or negative way?
 * What is the connection between the relevance of a topic an the quality of the article?

I research a sample of 450 articles from the german Wikipedia.

You'll find more information at http://editthispage.blogspot.com (german) or you can contact me at abraendle [at] gmx [dot] ch.

title: User:Rosskurator~enwikibooks


text:
Guitar/Playing With Others

Almost as soon as you start playing the guitar, you start to meet many other guitarists. Eventually, you will wind up playing with some of them, in some sort of informal jam sessions, where friends play anything that tickles their fancy.

Playing with others is helped incredibly by having some basic knowledge of music theory along with some amount of talent or skill. This is especially true if you intend to improvise a melody or chord progression. this section will provide the basics of considerate playing, along with some tips on how to keep playing interesting.

The Makeup of a Band
Even if you never intend to play in a large group, it's still important to know the basic divisions of a band, because you never know what might happen tomorrow. Learning about how a band works can also help you learn new songs from popular groups, as well as improve your knowledge of general music theory, and your appreciation for music.

As explained in the lead guitar and rhythm guitar section, guitar playing essentially breaks down to two, somewhat overlapping categories; rhythm and lead (sometimes called melody). In a band, the rhythm guitar is more generally associated with the drums, bass, background vocals and less prominent instruments, while the melody guitar would be related to the lead vocals or any other lead instrument.

Thus, when you are playing only with two people, almost immediately one player provides the chords and groove of a song, while another play contributes a melody that complements the song's progression. With more people playing, this division becomes less strict, and players can shift from playing more of less prominent parts.

In general, it is almost always better to play with more than two people, because with more people, whatever piece you are playing is less likely to fall apart when the first person screws up. If you only play with one other person, consider including a metronome or a mp3 drum track in the background. Electronic accompaniment helps you keep a steady pace, and helps you learn to not "rush" or "drag" in the group.

Proper Playing Attitudes
The most important thing to remember about playing with others can be learned by carefully listening to any piece of recorded music: Every player contributes to the song with an appropriate tone and volume, and never plays in excess of that. Essentially this just means you shouldn't try to outplay and outshine everyone else in the group, because no one likes a showoff. It doesn't matter how good you are (or think you are), you should never play so much that it drowns everyone else out.

If not overplaying is the most important thing about jamming, then the second most important is listening. The key to improvisation is to listen to the interplay of all the other instruments, and to add to that whatever sounds best. Listening is, unfortunately, a very neglected skill among beginning musicians, and really, most musicians in general.

A common tendency, especially among those who have just begun to get a solid foundation in scale theory and technique, is to noodle around aimlessly on the fretboard with little or no regard for the shape of the song that is being played, or the structure of the arrangement. This is a huge mistake, and it leads to music that no one wants to listen to; worse yet, it does nothing to develop the musician who plays it.

Pay attention to the music that is being played around you. Add to it only when it is necessary. You should begin to hear the lines that you want to play before you play them. What you are shooting for here is something akin to the old koan about sculpting: the figure is already in the marble, and you are just trying to release it.

It is also important to make sure that you do not take up too much "space" in the arrangement, which is to say, do not play so loudly that other instruments must fight to be heard. This is especially a problem for rhythm guitarists in jam sessions, who must be careful not to drown out soloists.

Staying in the Right Key
Perhaps the most important thing to do when playing with others is to remember what key you are in. The "key" of a piece is essentially the scale of notes that the song uses, but it also affects what the correct chords are to play on each note. Suppose there is only yourself and another guitarist playing, and the other guitarist is playing rhythm. The chord progression they are playing determines the key of the song, which naturally suggests certain notes for you, the lead guitarist.

Even if you have absolutely no knowledge of music theory, everyone can generally tell when you play a wrong note. Although advanced players can often add in "wrong" notes for colour (known in music theory as an accidental), for beginners it is important to know what notes are in what keys, so they can use the most appropriate notes.

For example, the rhythm guitarist might be playing a three chord blues riff in the key of B minor. Even if you didn't know the key, often the first and last chord of a progression can be good indicators of commonly used keys. At the very least, the general tone of the progression will be enough to indicate if it is a major or minor key. in this case, once you knew the key, you could immediately start soling in any B minor scale, such as the B minor pentatonic scale. However, since music is creative, it is impossible to be "limited", and you also have available a number of other soloing scales, like the pentatonic scale or any of the modes. For example, the Phrygian mode has traditionally been the "Spanish scale". Modes are much more complex and require knowledge of music theory to get the most benefit from them.

Improvising
There is also a basic approach to improvising which is more simple than playing over a chord accompaniment. It also predates Western tuning systems and chords. It is produced by playing a moving melody on one higher-pitched string, while leaving a lower note ringing on another "open", or lower-pitched (unfretted) string. The static bass note is referred to as a "pedal tone". The lower note or stays the same and the upper note moves, creating both simple harmonic and melodic motion. Traditional instruments which have fewer strings and a smaller range than the guitar use this technique. It can be heard in many musical styles in both Eastern and Western musical traditions including those with guitar.

This technique can be found both within Western tuning systems which use 12 semitones per octave as well as beyond in more complex Eastern tuning systems. Therefore before attempting to improvise a solo over a chord progression or a series of chords in a particular key, it is useful to practice playing simple melodies on one (upper) string to familiarize your ear with the intervals, or distances between those fretted notes and a static open, un-fretted (lower) string below it which is sounding simultaneously. Another advantage of this is that with each pair of notes you play, different intervals are sounded. Your ear begins to detect these and this is a basic form of ear training.

title: Guitar/Playing With Others


text:
Cookbook:Six Layer Casserole

| Meat Recipes | Midwestern U.S. cuisine

Six layer casserole is a great recipe for when friends are visiting. The preparation can all be done hours in advance.

Ingredients

 * 2 cups diced potatoes
 * 1 cup carrots diced
 * ½ cup diced onion
 * ½ cup raw rice
 * 1 lb ground beef
 * 10 oz canned tomato soup (you may also use homemade tomato sauce)
 * 2 cups water
 * salt and pepper

Procedure

 * 1) Spread layers of raw vegetables and rice in a 9x9-inch baking dish in the order mentioned above and crumble raw hamburger on the top.
 * 2) Mix the soup and water and pour over all.
 * 3) Add salt and pepper on top.
 * 4) Bake about 1.5–2 hours at 350°F.

Notes, tips, and variations

 * After dishing some of the casserole to your plate, spread ketchup over the top. It may sound odd but it tastes great.
 * If you double the recipe, use a tall 9x13-inch baking dish and bake it a little longer.

title: Cookbook:Six Layer Casserole


text:
How to Write an Essay/Parts

Parts of an Essay — Traditionally, it has been taught that a formal essay consists of three parts: the introductory paragraph or introduction, the body paragraphs, and the concluding paragraph. An essay does not need to be this simple, but it is a good starting point.

Introductory Paragraph
The introductory paragraph accomplishes three purposes: it captures the reader’s interest, it suggests the importance of the essay’s topic, and it ends with a thesis sentence. Often, the thesis sentence states a claim that consists of two or more related points. For example, a thesis might read:
 *  A college essay has an introductory paragraph, several body paragraphs, and a concluding paragraph.

You are telling the reader what you think are the most important points which need to be addressed in your essay. For this reason, you need to relate the introduction directly to the question or topic. A strong thesis is essential to a good essay, as each paragraph of your essay should be related back to your thesis or else deleted. Thus, the thesis establishes the key foundation for your essay. A strong thesis not only states an idea but also uses solid examples to back it up. A weak thesis might be:
 *  Wikipedia is a powerful resource in many ways.

As an alternative, a strong thesis for the same topic would be:
 *  Wikipedia is a powerful resource because it allows users with knowledge in a specific area to share their knowledge, because it allows users to quickly find information about a vast array of topics, and because studies have confirmed that it is as accurate as any other encyclopedia.

Then, you could separate your body paragraphs into three sections: one explaining the open-source nature of the project, one explaining the variety and depth of information, and a final one using studies to confirm that Wikipedia is indeed as accurate as other encyclopedias.

Tips
Often, writing an introductory paragraph is the most difficult part of writing an essay. Facing a blank page can be daunting. Here are some suggestions for getting started. First, determine the context in which you want to place your topic. In other words, identify an overarching category in which you would place your topic, and then introduce your topic as a case-in-point.

For example, if you are writing about dogs, you may begin by speaking about friends, dogs being an example of a very good friend. Alternatively, you can begin with a sentence on selective breeding, dogs being an example of extensive selective breeding. You can also begin with a sentence on means of protection, dogs being an example of a good way to stay safe. The context is the starting point for your introductory paragraph. The topic or thesis sentence is the ending point. Once the starting point and ending point are determined, it will be much easier to connect these points with the narrative of the opening paragraph.

A good thesis statement, for example, if you are writing about dogs being very good friends, you could put:
 *  A dog is an example of a very good friend because of X, Y, and Z.

Here, X, Y, and Z would be the topics explained in your body paragraphs. In the format of one such instance, X would be the topic of the second paragraph, Y would be the topic of the third paragraph, and Z would be the topic of the fourth paragraph, followed by a conclusion, in which you would summarize the thesis statement.

Example

 *  As we travel through our lives, we will identify many people as friends. In truth, most of these individuals are simply acquaintances. They will enter and depart from our existence as matters of mutual convenience. True friends will be there for you always. There is no friend truer than a dog.

Identifying a context can help shape the topic or thesis. Here, the writer decided to write about dogs. Then, the writer selected friends as the context, dogs being good examples of friends. This shaped the topic and narrowed the focus to dogs as friends. This would make writing the remainder of the essay much easier because it allows the writer to focus on aspects of dogs that make them good friends.

Body Paragraphs
Each body paragraph begins with a topic sentence. If the thesis contains multiple points or assertions, each body paragraph should support or justify them, preferably in the order the assertions originally stated in the thesis. Thus, the topic sentence for the first body paragraph will refer to the first point in the thesis sentence and the topic sentence for the second body paragraph will refer to the second point in the thesis sentence. Generally, if the thesis sentence contains three related points, there should be three body paragraphs, though you should base the number of paragraphs on the number of supporting points needed.

If the core topic of the essay is the format of college essays, the thesis sentence might read:
 *  A college essay has an introductory paragraph, several body paragraphs, and a concluding paragraph.

The topic sentence for the first body paragraph might read:
 *  The first paragraph of an essay is the introductory paragraph.

Sequentially, the topic sentence for the second body paragraph might read:
 *  The introductory paragraph is followed by several body paragraphs.

And the topic sentence for the third body paragraph might read:
 *  The college essay’s final paragraph is its concluding paragraph.

Every body paragraph uses specific details, such as anecdotes, comparisons and contrasts, definitions, examples, expert opinions, explanations, facts, and statistics to support and develop the claim that its topic sentence makes.

Tips
When writing an essay for a class assignment, make sure to follow your teacher or professor’s suggestions. Most teachers will reward creativity and thoughtful organization over dogmatic adherence to a prescribed structure. Many will not. If you are not sure how your teacher will respond to a specific structure, ask.

Organizing your essay around the thesis sentence should begin with arranging the supporting elements to justify the assertion put forth in the thesis sentence. Not all thesis sentences will, or should, lay out each of the points you will cover in your essay. In the example introductory paragraph on dogs, the thesis sentence reads, “There is no friend truer than a dog.” Here, it is the task of the body paragraphs to justify or prove the truth of this assertion, as the writer did not specify what points they would cover. The writer may next ask what characteristics dogs have that make them true friends. Each characteristic may be the topic of a body paragraph. Loyalty, companionship, protection, and assistance are all terms that the writer could apply to dogs as friends. Note that if the writer puts dogs in a different context, for example, working dogs, the thesis might be different, and they would be focusing on other aspects of dogs.

It is often effective to end a body paragraph with a sentence that rationalizes its presence in the essay. Ending a body paragraph without some sense of closure may cause the thought to sound incomplete.

Each body paragraph is something like a miniature essay in that they each need an introductory sentence that sounds important and interesting, and that they each need a good closing sentence in order to produce a smooth transition between one point and the next. Body paragraphs can be long or short. It depends on the idea you want to develop in your paragraph. Depending on the specific style of the essay, you may be able to use very short paragraphs to signal a change of subject or to explain how the rest of the essay is organized.

Do not spend too long on any one point. Providing extensive background may interest some readers, but others would find it tiresome. Keep in mind that the main importance of an essay is to provide a basic background on a subject and, hopefully, to spark enough interest to induce further reading.

Example

 *  A true friend will be there for you whenever you need them. Any dog owner will say that there is nobody that will stick with you through thick and thin as much as a dog. My own dog can barely contain her joy when I come home from a hard day. Regardless of my mood, and my attitude towards her, she is always happy when I am home, and that is usually enough to make me feel better about everything.

 *  True friends will help you when you are in need. Whether it is to protect their owner against some sort of threat or to help a blind person walk across the street, dogs are the most reliable companion a person could have. Few villains would attack a person walking a dog at night, and statistics show that homes with dogs are among the least likely to be broken into parts

The above example is a bit free-flowing and the writer intended it to be persuasive. The second paragraph combines various attributes of dogs including protection and companionship. Here is when doing a little research can also help. Imagine how much more effective the last statement would be if the writer cited some specific statistics and backed them up with a reliable reference.

Concluding Paragraph
The concluding paragraph usually restates the thesis and leaves the reader something about the topic to think about. If appropriate, it may also issue a call to act, inviting the reader to take a specific course of action with regard to the points that the essay presented.

Aristotle suggested that speakers and, by extension, writers should tell their audience what they are going to say, say it, and then tell them what they have said. The three-part essay model, consisting of an introductory paragraph, several body paragraphs, and a concluding paragraph, follows this strategy.

Tips
As with all writing, it is important to know your audience. All writing is persuasive, and if you write with your audience in mind, it will make your argument much more persuasive to that particular audience. When writing for a class assignment, the audience is your teacher. Depending on the assignment, the point of the essay may have nothing to do with the assigned topic. In most class assignments, the purpose is to persuade your teacher that you have a good grasp of grammar and spelling, that you can organize your thoughts in a comprehensive manner, and, perhaps, that you are capable of following instructions and adhering to some dogmatic formula the teacher regards as an essay. It is much easier to persuade your teacher that you have these capabilities if you can make your essay interesting to read at the same time. Place yourself in your teacher’s position and try to imagine reading one formulaic essay after another. If you want yours to stand out, capture your teacher’s attention and make your essay interesting, funny, or compelling.

Example

 *  It is no accident that many people consider their dogs as part of their family. Just like every other member, dogs contribute to the happiness and well-being of the home, making the burdens of caring for them well worth the effort. Dogs deserve love and respect every bit as much as they love and respect us. After all, what more can a friend be?

In the above example, the focus shifted slightly and talked about dogs as members of the family. Many would suggest it departs from the logical organization of the rest of the essay, and some teachers may consider it unrelated and take points away. However, contrary to the common wisdom of “tell them what you are going to say, say it, and then tell them what you have said,” you may find it more interesting and persuasive to shift away from it as the writer did here, and then, in the end, return to the core point of the essay. This gives an additional effect to what an audience would otherwise consider a very boring conclusion.

title: How to Write an Essay/Parts


text:
Cookbook:Bengali Five-Spice Mix (Panch Puran)

| Cuisine of India | Spices and herbs

Panch Puran (also called Panch Phoran, Panch Phoron, or Bengali Five-Spice Mix) is a spice mixture used in Indian cuisine. It is made of equal parts of five spices:

 * fenugreek seed (methi)
 * nigella seed (kalo jira)
 * mustard seed (rai or shorshe)
 * fennel seed (mouri)
 * cumin seed (jeera)

In some variations, wild onion is used in place of cumin. In other variations, radhuni seed is added to the mixture.

The name simply means "five spices" in Bengali.

In Bengali cuisine, the seeds are usually fried in oil (or ghee), which causes them to start crackling immediately. Vegetables (especially potatoes), dal, or fish are then added. It is not used with meat.


text:
User:Camilo Acosta

LIMITES
Esta pagina fue creada en un segundo intento mio de pasar calculo diferencial estudiando ingenieria de sistemas en la universidad javeriana de colombia

el objetivo aunque absurdo era de colocar lo que se pudiera en ejercicios en un pagina asi este ayudaba a la nota final y tratar de pasar la nota, el profesor que un total mediocre para explicar no tenia ni idea de nada

espero les sea de alguna ayuda ya que para mi no fue por que igual perdi la materia por 2 vez::

Camilo Acosta

1)$$f(x) = \left\{\begin{matrix} \frac {\sqrt[2]-2}{x-4}, & \mbox{si }x \ne 4 \\ \frac {1}{4}, & \mbox{si }x = 4 \end{matrix}\right. $$ User:Camilo_Acosta 41 By Camilo_acosta
 * $$ F(x)\sqrt[2]$$
 * $$\lim_{x \rightarrow -2^+} F(x) =\lim_{x \rightarrow -2^+} \sqrt[2]$$
 * $$\lim_{x \rightarrow -2^+} F(x) =0$$
 * $$\lim_{x \rightarrow -2^+} F(x) =F(-2)$$

 * $$\lim_{x \rightarrow -2^-} F(x) =\lim_{x \rightarrow -2^-} \sqrt[2]$$
 * $$\lim_{x \rightarrow -2^+} F(x) =0$$
 * $$\lim_{x \rightarrow -2^+} F(x) =F(2)$$

asimismo, F es continua por la derecha en -2 y es continua por la izquierda en 2. En efecto f es continua en el intervalo cerrado [-2,2]

by Camilo_Acosta

2) by Camilo_Acosta
 * $$\lim_{x \rightarrow 2}\frac {x^2-4}{x-2}=\frac {(x-2)(x+2)}{x-2}={x+2}$$

 * $$\lim_{x \rightarrow 2}{x+2}=4$$

By camilo_acosta

3) By camilo_Acosta
 * $$\lim_{x \rightarrow 3}\frac {x^3-21}{x^2-9}=\frac {(x-3)(x^2+3x+9)}{(x-3)(x+3)}=\frac{(x^2+3x+9)}{x+3}$$
 * $$\lim_{x \rightarrow 3}\frac {(x^2+3x+9)}{x+3}= \frac {27}{6}$$

By Camilo_acosta

4) By camilo_acosta

 * $$\lim_{x \rightarrow 2}\frac {\sqrt[2]-\sqrt[2]}{x-2}=inderterminado$$
 * $$\lim_{x \rightarrow 2}\frac {\sqrt[2]-\sqrt[2]}{x-2}* \frac{\sqrt[2]+\sqrt[2]}{\sqrt[2]+\sqrt[2]}$$
 * $$\lim_{x \rightarrow 2}\frac {x-2}{(x-2)(\sqrt[2]+\sqrt[2])}$$
 * $$\lim_{x \rightarrow 2}\frac {1}{2\sqrt[2]}$$
 * $$\frac {2\sqrt[2]}{4}$$

5) by Camilo_Acosta
 * 1) $$\lim_{x \rightarrow 0}\frac {\sqrt[2]-3}{x}=inderterminado$$
 * 2) $$\lim_{x \rightarrow 0}\frac {\sqrt[2]-3}{x}* \frac{\sqrt[2]+3}{x{\sqrt[2]+3}} $$
 * 3) $$\lim_{x \rightarrow 0}\frac {9+x-9}{x(\sqrt[2]+3)} $$
 * 4) $$\lim_{x \rightarrow 0}\frac {1}{\sqrt[2]+3} $$
 * 5) $$\lim_{x \rightarrow 0}\frac {1}{6} $$

6) By Camilo_Acosta
 * 1) $$\lim_{x \rightarrow 5}\frac {x^2-25}{x-5}=inderterminado$$
 * 2) $$\lim_{x \rightarrow 5}\frac {x^2-25}{x-5}*\frac {(x-5)(x+5)}{x-5}$$
 * 3) $$\lim_{x \rightarrow 5} {x+5}$$
 * 4) $$\lim_{x \rightarrow 5}10$$

by Camilo_Acosta

7) by Camilo_Acosta (nota: este límite da "límite cuando x tiende a 2 de raíz cuadrada de 7 entre 3"; se debe modificar el ejercicio para que de la indeterimnación... ¿No me creen?, pues prueben los valores de x=2 para que vean

 * 1) $$\lim_{x \rightarrow 2}\sqrt[2]{\frac{x^3+2x+3}{x^2+5}}=inderterminado$$
 * 2) $$\lim_{x \rightarrow 2}\sqrt[2]{\frac{x^3+2x+3}{x^2+5}}=\sqrt[2]{\lim_{x \rightarrow 2}\frac{x^3+2x+3}{x^2+5}}$$
 * 3) $$\lim_{x \rightarrow 2}\sqrt[2]{\frac{x^3+2x+3}{x^2+5}}=\sqrt[2]{\frac{\lim_{x \rightarrow 2}(x^3+2x+3)}{\lim_{x \rightarrow 2}(x^2+5)}}$$
 * 4) $$\lim_{x \rightarrow 2}\sqrt[2]{\frac{x^3+2x+3}{x^2+5}}=\sqrt[2]{\frac{\lim_{x \rightarrow 2}(x^3)+\lim_{x \rightarrow 2}(2x)+\lim_{x \rightarrow 2}(3)}{\lim_{x \rightarrow 2}(x^2)+\lim_{x \rightarrow 2}(5)}}$$
 * 5) $$\lim_{x \rightarrow 2}\sqrt[2]{\frac{x^3+2x+3}{x^2+5}}=\sqrt[2]{\frac{(\lim_{x \rightarrow 2}x)^3+\lim_{x \rightarrow 2}(2)*\lim_{x \rightarrow 2}(x)+\lim_{x \rightarrow 2}(3)}{(\lim_{x \rightarrow 2}x)^2+\lim_{x \rightarrow 2}(5)}}$$
 * 6) $$\lim_{x \rightarrow 2}\sqrt[2]{\frac{x^3+2x+3}{x^2+5}}=\sqrt[2]{\frac{2^3+2*2+3}{2^2+5}}$$
 * 7) $$\lim_{x \rightarrow 2}\sqrt[2]{\frac{x^3+2x+3}{x^2+5}}=\sqrt[2]{\frac{8+4+3}{9}}$$
 * 8) $$\lim_{x \rightarrow 2}\sqrt[2]{\frac{x^3+2x+3}{x^2+5}}=\frac{\sqrt[2]{15}}{3}$$

by Camilo_Acosta

Maximos y Minimos
Encuentre los valores máximos y mínimos hayando a cada funcion su número crítico
 * $$\ f(x) = 2x^3-2x^2(2+x)$$
 * $$\ f'(x) = x^3-4x^2-8x(49x^3-2x^2)$$
 * $$\ 0 = 5x^3(4x^3+8x^2-32x-5x)$$
 * $$\ 0 = (5x+32x)^2-(8x-12)^2$$
 * $$\ f''(x) = (2x)^2+(4x^2+26)-54$$
 * $$\ f''(0) = 12x^2-54x(45+2x^2-35+22)$$
 * $$\ f(x) = 5x^3(-10x)^2+(4x-27)-2$$
 * $$\ f'(x) = -(3x^2)+(-8x)^4$$
 * $$\ 0 = (-3x^3-8x^2+4)+5x(-42)$$
 * $$\ 0 = (-(-x-2)+(3x^2(-2)-(2x)$$
 * $$\ f''(x) = 6x^2(-8)+(3x^3-25)$$

 * $$\ f'(x) = 9x^4(-7x)^2+{(x)}^2$$
 * $$\ f'(x) = -x^3-54x(81)-(-x)-(12x)^2-8x)^2)^3)^-$$
 * $$\ 0 = (x^3)(-4x)^6-(+(-)9$$
 * $$\ 0 = x^7+(4)^(4x^2-54)$$
 * $$\ x_1 = 5x-3x-^2(-(-x-2)+(3x^2)+x-1)$$
 * $$\ x_2 = x-3(-1(^2$$    \sqrt[2]
 * $$\ x^2 = 4$$
 * $$\ x^3 = \frac{24}{4x}$$
 * $$\ f''(x) = 12x^2-54$$
 * $$\ f''(0) = 12(0)^2-54$$
 * $$\ f''(0) = -12x(4)$$ Máximo

3):$$\ f(x) = -x^3x^3-4x^3)(-4x)^6-9x^2+4x-1$$
 * $$\ f'(x) = x^2-(+)8x^+4$$
 * $$\ 0 = (3)x^2-8-x^4-x+3-4^x(^7)$$

by Camilo_Acosta

Problemas de razón de cambio
1) se suleta un globo en un punto a 150 pies de un observador, quien se encuentra al nivel del piso. si el globo se eleva en línea recta hacia arriba a una velocidad de 8 pies por segundo,¿ qué tan rápido esta aumentando la distancia del observador al globo cuando el globo esta a 50 pies de altura?(supongase que el globo se suleta desde el nivel del piso)

solución sea t el número de segundos contados a partir de que se suelta el globo. sea h la altura del globo y s su distancia al observador. tanto h como s son variables que dependen de t; sin embargo, permanece sin cambio conforme t aumenta. obsevemos que al inicio, s casi no cambia (ds/dt=0), pero eventualmente s cambia casi tan rapido como cambia h (ds/dt=dh/dt=8). Una Estimaciónde ds/dt cuando h=50 podría ser alrededor de un tercio o e un medio de dh/dt, o 3. si obtenemos una respuest alejada de este valor, sabremos que hemos cometido un error. Por ejemplo, respuesta tales como 17 o aun 7, obviamente son incorrectas.

Para enfatizar, respondemos tres preguntas fundamentales

(a) ¿Qué esta dado?RESPUESTA dh/dt=8 (b) ¿Qué queremos conocer?RESPUESTA: queremos conocer ds/dt en el instante en que h=50 (c) ¿Como estan relacionadas s y h? las variables s y h cambian con el tiempo, pero siempre estan relacionadas por medio de la ecuación pitragórica --- Los puntos a y b estan en las orillas de un rio recto de 3 km de ancho y son opuestos uno del otro. El punto C esta en la misma orilla que b pero a "K" kilometros de "B" rio abaj. Una compaia telefonica desea tender un cable de "A" y "C" donde costo por kilometro de cable en tierra es de $10000 y el de cable subacuatico es de $ 12500.Sea p un punto en la misma orilla que B y C de modo que el cable se tienda de "A" a "P y luego a C.

a-) SI x kilometros es la distancia de B a P, obtenga una ecuacion que defina a C(x) si C(x) dolares es el costo total del cable tendido y establezca el dominio de c.

respuesta

La distancia de P a C es de (K-X9 kilometros y del teorema de pitagoras de a a p es $$\sqrt[2]{3^2 + x^2} $$kilometros. por lo tanto

$$c(x) = 12500 \sqrt[2]{3^2 + x^2}+10000(k-x)$$ El dominio de C es [0, k]

Un fabricante de cajas de carton quiere elaborar cajas abiertas a partir de trozos rectangulares de carton con dimensiones de 10 pulg por 17 pulg, cortando cuadrados en las esquinas y doblando los lados hacia arriba. Se desea determinar la longitud del lado de los cuadrados que se deben cortar de modo que la caja tenga el mayor volumen posible.

$$v(x) = 170x-54x^2+4x^3$$

y el dominio de v es el intervalo cerrado [0.5] Como v es continua en [0.5]se sabe que el valor v tiene un valor maximo absoluto el cual ocurre en un numero critico o en un extremo del intervalo. para obtener los numeros criticos se calcula v'(x) = 0 o no existe

V'(x) = 170-108x+12^2

V'(x) existe para todos los valores de x. Al igualar V'(x) a cero y despejar x se tiene

2(6x^2-54x+85)=0

$$v(x) =\frac{54+\sqrt[2]{(-54)^2-4(6)(85)}}{12}$$ De donde se obtiene x=6.27 y x=2.03.De modo que el unico valor critico de V en [0.5] es 2.03 como v(0)=0 y v(5)=0, mientras que V(2.03)=156.03, el valor absoluto de V ocurre cuando x=2.03

Conclusion El mayor volumen posible es 156.03 pulga^3 y se obtiene cuando la longitud sw loa lados de los cuadrados que se cortaran es de 2.03 pulg.

Una escalera de 25 pie de longitud esta apoyada contra la pared vertical. La base de la escalera se jala horizontalmente alejandola de la pared a 3 pie/s. Suponga que se desea determinar que tan rapido se desliza hacia abajo la parte superior de la escalera sobre la pared cuando su base se encuentra a 15 pies de la pared.

I: El numero de segundos del tiempo que ha transcurrido desde que la escalera comenzo a deslizarse hacia abajo sobre la pared.

X: El numero de pies de la distancia desde la base de la escalera a la pared a los 't' segundos

Y:El numero de pies de la distancia desde el piso a la parte superior de la escalera a los t segundos

Como la base de la escalera es jalada horizontalmente alejandola de la pared a 3/pies $$\frac{dx}{dt}=3$$

$$Se desea determinar

Escriba una ecuacion que relacione a 'X','Y' y del teorema de pitagoras

y^2=625-x^2

Se deriva con respecto a t

sustituya los valores conocidos de x,y y y en la ecuacion anterior para

Cuando x=15 de (1) y= 20. como se obtiene de (2)

el signo indica que decrece conforme t aumenta

La parte superior de la escalera se desliza hacia abajo sobre la pared a la tasa de 2.25 pies/s cuando la base esta a 15 pie de la pared

Cierta cantidad de agua fluye a una tasa de 2m^3 hacia el interior de un deposito cuya forma es la de un cono invertido de 16 m de altura y 4 m de radio ¿que tab rapido sube el nivel del agua cuando esta ha alcanzado 5 m de profundidad?

t:El numero de minutos del tiempo que ha trascurrido desde que el agua comenzo a fluir dentro del tanque

h:El numero de metros de altura del nivel del agua a los t minutos

r:el numero de metros del radio de la superficie del agua a los t minutos

v:el numero de metros cubicos del volumen de agua en el tanque a los t minutos. observe que v, r y h son funciones de t

puesto que el agua fluye dentro del tanque a una tasa de 2 m^3/min

entonces

se desea determinar

en cualquier tiempo el volumen del agua en el tanque puede expresarse como el volumen de un cono

Se conoce y se desea determinar $$\frac{dh}{dy} por lo tanto se nesesita una ecuacion que involucre a V y h. Asi primero se expresa r en terminos de h.

$$\frac {r}{h}pi(\frac{4}{16})^2(h)=v=\frac{1}{48}pih^3$$

Al diferenciar los dos miembros de esta ecuacion con respecto a t $$\frac {dv}{dt}=\frac{1}{16}pih^2(h).\frac{dh}{dt}$$

ahora se sustituye 2 por $$\frac{dv}{dt}\frac{dh}{dt}$$y se resuelve la ecuacion para

$$\frac{dh}{dt}=\frac{32}{pih^2}$$

asi,

$$\frac{dh}{dt}=\frac{32}{25pi}$$

al convertir metros a centimetros se tiene=0.4074 m/min=40.74 cm/min.

El nivel del agua sube a una tasa de 40.74 cm/min cuando el agua ha alcanza una profundidad de 5 m.

Defina pi=π

Dos automoviles, uno va hacia el este a una tas a de 90 km/h, y el otro hacia el sur a 60 km/h, se dirigen hacia la interseccion de os carreteras. ¿a que tasa se estan aproximando uno al otro en el instante en que el primer automovil esta 0.2 km de la interseccion y el segundo se encuentra a 0.15 km de dicha interseccion?

t: el numero de horas del tiempo que ha trascurrido desde que los automoviles empezaron a aproximarse a p.

x:el numero de kilometros de la distancia a partir del primer automovil a p a las t horas

y:el numero de kilometros de la distancia a partir del segundo automovil a p a las t horas

z:el numero de kilometros de la distancia entre los dos automoviles a la t horas

Como el primer carro se acerca a p a una tasa de variacion de - km/h90 y x esta decreciendo conforme t crece, entonces $$\frac{dx}{dt}=-90$$ de la misma manera $$\frac{dy}{dt}=-60$$

Se desea determinar $$\frac{dz}{dt}$$ cuando x=0.2 y y=0.15

Del teorema de pitagoras

$$z^2=x^2+y^2$$

al diferenciar los dos miembros de (4) con respecto a t, se obtiene $$2z\frac {dz}{dt}=2x\frac{dx}{dt}+2y\frac{dy}{dt}$$

$$\frac {dz}{dt}=\frac{x\frac{dx}{dt}+y\frac{dy}{dt}}{z}$$

Cuando x=0.2 y y=0.15 de (4) se tiene que z=0.25 en (5) se sustituyen$$\frac{dx}{dt} por -90$${dy}{dt} por -60, x por 0.2 y por 0.15 y z por 0.25 para obtener

=-108

En el instante en cuestion, los carros se aproximan uno al otro a una tasa de 108 km\h

Suponga que en cierto mercado, x miles de canastillas se surten diariamente cuando p dolares es el precio por la canastilla. La ecuacion de oferta es

p(x)-20p-3x+105=0

Si el suministro diario decrece a una tasa de 250 canastillas por dia,¿a que tasa esta variando el precio cuando la oferta diaria la oferta diaria es de 5000 canastillas?

Sea t dias el tiempo que ha transcurrido desde que el simnistro diario empezo a decrecer la variable p y x estan definidas como funciones de t en el enunciado del problema. debido a que el suministro diario esta decreciendo a una tasa de cambio de 250 canastillas por dia,entonces $$\frac{dx}{dt}=-\frac{250}{1000}$$, $$\frac{dx}{dy}=-\frac{1}{4}$$ Se desea determinar $$\frac{dp}{dt}$$ Cuando x=5 De la ecuacion de oferta dada, al diferenciar implicitamente con respecto a t se obtiene

$$p\frac{dx}{dt}+x\frac{dp}{dt}-3\frac{dx}{dt}=0$$

$$\frac{dp}{dt}=\frac{3-p}{x-20}.\frac{dx}{dt}$$

Cuando x=5, se deduce de la ecuacion de oferta que p=6

Debido a que $$\frac{dx}{dt}=\frac-{1}{4}$$ Se tiene la ecuacion anterior

$$\frac{3-6}{5-20}*\frac{-1}{4}$$ $$\frac{-1}{20}$$

El precio de la canastilla de naranjas esta decreciendo a la tada de $0.05 por dia cuando la oferta diaria es de 5000 canastaillas.

Un avion vuela hacia el oeste con una velocidad de 500/pies a una altura de 4000 pie y un rayo de luz de un faro de rastreo ubicado en tierra, incide en la parte inferior del avion. Si la luz se mantiene sobre el avion ¿que tan rapido gira el rayo de luz cuando el avion se encuentra a una distancia horizontal de 2000 pies al este del faro.

t: segundos el tiempo que transcurre desde que la luz del faro incidio en el avion x:el numero de pies hacia el este de la distacia horizontal del avion des de el faro a los t segundos

Rad:el numero de radianes del angulo de elevacion del avion desde el faro a los t segundos

puesto que $$\frac{dx}{dt}=-500$$ y como se desea determinar $$\frac{drad}{dt}$$ cuando x=2000,se considera $$tanrad=\frac{4000}{4}$$ al diferenciar los dos miembros de esta ecuacion con respectp a t se obtiene $$sec^2rad=\frac{4000}{x^2}*\frac{dx}{dt}$$ Si se sustituye $$\frac{dx}{dt}*-500$$en la ecuacion anterior y al dividir entre $$sec^2rad$$ Se tiene

$$\frac{drad}{dt}=\frac{2000000}{x^2sec^2rad}$$ $$\frac{drad}{dt}=\frac{1}{10}$$

Problemas de maximos y minimos
Sea la funcion definida $$\frac{x}{1-x^2}$$ no tiene valor absoluto ni valor minimo absoluto en el intervalo (-1,1)

 * $$\lim_{x \rightarrow -1^+}f(x)=-\infin$$
 * $$\lim_{x \rightarrow -1^-}f(x)=+\infin$$

La funcion definida por f(x)=\frac{1}{x-3} no tiene valro maximo absoluto ni valor minimo absoluto en[2,4].Como $$\lim_{x \rightarrow 3^-}f(x)=-\infin$$F(x) puede hacerse menor que cualquier numero negativo tomando 3-x>o y menor que cualquier numero positivo tomando x-3>0 y menor que una

Suponga que f es la funcion definida por $$f(x)=2x$$ la grafica de f en el intervalo [1,4) esta funcion tiene un valor minimo absoluto de 2 en [1,4).No existe un valor maximo absoluto de f en [1,4) por que $$\lim_{x \rightarrow 4^-}f(x)=8$$, pero f(x)siempre es menor que 8 en el intervalo dado [[Image:Grafica11.bmp]]

La siguiente funcion f definida $$F(x)=-x^2$$ La grafica de f en el intervalo (-3,2]. Esta funcion tiene valor maximo absoluto de 0 en (-3,2]. No existe un valor absoluto de f en (-3,2] debido a que $$\lim_{x \rightarrow 3^+}f(x)=9$$pero F(x) siempre es mayor que -9 en el intervalo dado.

Sea f la funcion definida por $$f(x)=x^2-4x+5$$

entonces $$f=2x-4x$$

Como$$f'(2)=0$$ f puede tener un extremo relativo en 2. Puesto que f(2)=1 y 1f(x) cuando x<1 y 21 de modo que f no tiene un extremo relativo. la grafica de esta funcion tiene un recta tangente horizontal en el punto (1,2), lo cual es consistente con el echo de que la derivada sea cero en ese punto.

Sea f la funcion definida por $$f(x) = \left\{\begin{matrix}2x-1, & \mbox{si }x < 4 \\8-x & \mbox{si }3 < x \end{matrix}\right. $$

tiene un valor relativo en 3, la derivada por la izquierda en 3 esta dada por f'+(3)=-1 por lo tanto, se concluye que f'(3) no existe.

Es posible que una funcion pueda estar definida en un numero c donde f'(c) no exista y sin embargo, f'(c) no exista y sin embargo f no tenga un extremo relativo en ese numero.

Sea la funcion

$$F(x)=x^\frac{1}{3}$$ El dominio de f es el conjunto de todos lo numeros reales, y su derivada

$$f'(x)=\frac{1}{3x^\frac{2}{3}}$$

Ademas f'(0) no existe, la funcion no tiene extremos relativos. en resumen si na funcion f esta definida en un numero c, una condicion necesaria para que f tenga un extremo relativo en c es que f'(c)=0 o que f'(c) no exista.Tenga en cuenta que esta condicion es nesesaria pero no suficiente

PUNTOS CRITICOS
Sea la funcion definida por $$f(x)=x^4+4x^3-2x^2-12x$$

Estime los numeros criticos

Como F'(x) es un polinomio f'(x) existe en todo numero. Por lo tanto los unicos criticos son aquellos valores de x para los que f'(x)=0 esto es, las coordenadas x de los puntos de la grafica de f para los que la recta tangente es horizontal.

Se calculaF'(x) se iguala a cero y se despeja x.

 * $$4x^3+12^2-4x-12=0$$
 * $$x^3+3x^2-x-3=0$$
 * $$x^2(x+3)-(x+3)=0$$
 * $$(x+3)(x^2-1)=0$$
 * $$x+3=0$$
 * $$x=-3$$

 * $$x^2-1=0$$

 * $$x^2=1$$

 * $$x=\pm1$$

De este modo se ha confirmado que los numeros critivos son -3, -1 y 1

Determine los numeros criticos de la funcion definida por

 * $$f(x)=x^\frac{4}{3}+4x^\frac{1}{3}$$
 * $$f'(x)=\frac{4}{3}x^\frac{-2}{3}*(x+1)$$
 * $$f'(x)=\frac{4(x+1)}{3x^\frac{2}{3}}$$

Cuando x=-1 f'(x) =0 y cuando F'(x) no existe. Tanto -1 como 0 estan en el dominio de f por los numeros crticos de f son -1 y 0

DERIVADAS

 * $$(3x^2-5)(2x^4-x)$$
 * $$(3x^2-5)(2x^4-x)=(3x^2-5)Dx(2x^4-x)+(2x^4-x)Dx(3x^2-5)$$
 * $$(3x^2-5)(2x^4-x)=(3x^2-5)(8x^3-1)+(2x^4-x)(6x)$$
 * $$(3x^2-5)(2x^4-x)=(24x^5-3x^2-40x^3+5+12x^5-6x^2$$
 * $$(3x^2-5)(2x^4-x)=(36x^5-40x^3-9x^2+5$$

para verificar multiplicamos y luego tomamos la derivada $$(3x^2-5)(2x^4-x)=6x^6-10x^4-3x^3+5x$$ Asi
 * $$Dx[(3x^2-5)(2x^4-x)]=Dx(6x^6)-Dx(10x^4)-Dx(3x^3)+Dx(5x)$$
 * $$Dx[(3x^2-5)(2x^4-x)]=36x^5-40x^3-9x^2+5$$

Ecuentre las derivadas de :$$5x^2+7x-6y4x^6-3x^5-10x^2+5x+16$$
 * $$Dx(5x^2+7x-6)=Dx(5x2+7)-Dx(6)$$
 * $$Dx(5x^2+7x-6)=Dx(5x2)+Dx(7x)-Dx(6)$$
 * $$Dx(5x^2+7x-6)=5Dx(x2)+7Dx(x)-Dx(6)$$
 * $$Dx(5x^2+7x-6)=5*2x+7*1+0$$
 * $$Dx(5x^2+7x-6)=10x+7$$

si :$$y=sen(x^3-3x)$$,encuentre Dxy podemos escribir y=sen u y u^3-3x

 * $$Dxy=Duy*Dxu$$
 * $$Dxy=(cosu)*(3x^2-3)$$
 * $$Dxy=[cos(x^3-3x)]*(3x^2-3)$$
 * $$Dxy=(3x^2-3) cos (x^3-3x)$$

Encuentre Dt
 * $$(\frac{t^3-2t+1}{t^4+3})^13$$
 * $$y=u^13$$
 * $$u=\frac{t^3-2t+1}{t^4+3}$$
 * $$Dty=Duy*Dtu$$
 * $$Dty=13u^12\frac{(t^4+3)(3t^2-2)-(t^3-2t+1)}{(t^4+3)^2}$$
 * $$Dty=13(\frac{t^3-2t+1}{t^4+3})^12*\frac{-t^6+6t^4-4t^3+9t^2-6}{(t^4+3)^2}$$

Encuentre :$$\frac{dy}{dx}$$, :$$si y=x^3-3x^2+7x$$

 * $$\frac{dy}{dx}=\frac{d}{dx}(x^3-3x^2+7x)$$
 * $$\frac{dy}{dx}=\frac{d(x^3)}{dx}-3\frac{d(x^2)}{dx}+7\frac{d(x)}{dx}$$
 * $$\frac{dy}{dx}=3x^2-3(2x)+7(1)$$
 * $$\frac{dy}{dx}=3x^2-6x+7$$

RECTA TANGENTE
Ecuentre una ecuacion de la recta tangente a la parabola $$y=x^2-1$$ en el punto (2,3)

 * $$\lim_{h \rightarrow 0}\frac {(x+h)-f(x)}{h}$$
 * $$\lim_{h \rightarrow 0}\frac {(x+h)-f(x)}{h}=\lim_{h \rightarrow 0}\frac {(2+h)^2-1)-f(x)}{h}$$
 * $$\lim_{h \rightarrow 0}\frac {(x+h)-f(x)}{h}=\lim_{h \rightarrow 0}\frac {(2+h)^2-1)-3}{h}$$
 * $$\lim_{h \rightarrow 0}\frac {(x+h)-f(x)}{h}=\lim_{h \rightarrow 0}\frac {(2+h)^2-4}{h}$$
 * $$\lim_{h \rightarrow 0}\frac {(x+h)-f(x)}{h}=\lim_{h \rightarrow 0}\frac {4+4h+h^2-4}{h}$$
 * $$\lim_{h \rightarrow 0}\frac {(x+h)-f(x)}{h}=\lim_{h \rightarrow 0}\frac {8h+h^2}{(h)^2}$$
 * $$\lim_{h \rightarrow 0}\frac {(x+h)-f(x)}{h}=\lim_{h \rightarrow 0}\frac {h(8+h)^2}{h}$$
 * $$\lim_{h \rightarrow 0}\frac {(x+h)^2)-f(x)}{(h)^2}=\lim_{h \rightarrow 0}(8+h)$$

by Camilo_Acosta

PROBLEMAS CON GRAFICAS

$$f(x)=\frac{1}{x-2}$$ Al grafica mostrada se rompe en el punto deonde x=2 por lo que se investigaran las condiciones

1 F(2) no esta definida

Como no se satisface la condicion anterior se sabe que es discontinua en ese punto esto se determina como discontinuidad esencial por que $$\lim_{x \rightarrow 2}f(x)$$ no existe.

Sea la funcion en la grafica Donde es discontinua en 4, el cual pertenece al intervalo cerrado [2,5] g(2)=-1 y g(5)=2. Si k es cualquier numero entre -1 y 2 no hay ningun valor de c entre 2 y 5 tal que g(c)=k. En particular, si k=1, entonces g(6)=1, pero no pertenece al intervalo (2,5)

Determine la asintota vertical de la grafica definida por $$f(x)=\frac{3}{x-3}$$

ahora determinamos los limites de la funcion

 * $$\lim_{x \rightarrow 3^+}=\infin$$
 * $$\lim_{x \rightarrow 3^-}=-\infin$$

Se concluye que la recta x=3 es una asintota vertical de la grafica de f. La grafica de f concluye la respuesta

Sea la siguiente funcion

$$f(x)=\frac{x^2+x+2}{x^2-2x-3}$$

Determine a):$$\lim_{x \rightarrow 3^+}$$ b):$$\lim_{x \rightarrow 3^-}$$ c)grafique

 * $$\lim_{x \rightarrow 3^+}\frac{x^2+x+2}{x^2-2x-3}=\lim_{x \rightarrow 3^+}\frac{x^2+x+2}{(x-3)(x-1)}$$

El limite del numerador es de 14, lo cual puede verificarse facilmente

 * $$\lim_{x \rightarrow 3^+}(x-3)(x-1)=\lim_{x \rightarrow 3^+}(x-3)*\lim_{x \rightarrow 3^+}(x+1)$$
 * $$\lim_{x \rightarrow 3^+}(x-3)(x-1)=0*4$$
 * $$\lim_{x \rightarrow 3^+}(x-3)(x-1)=0$$

El limite del denominador es 0 y el denominador se aproxima a 0 mediante valores positivos.

 * $$\lim_{x \rightarrow 3^+}\frac{x^2+x+2}{x^2-2x-3}=\infin$$

B)
 * $$\lim_{x \rightarrow 3^-}\frac{x^2+x+2}{(x-1)(x+1)}=\lim_{x \rightarrow 3^-}\frac{x^2+x+2}{(x-1)(x+1)}$$

En este caso, el limite del denominador es cero, pero el denominador se aproxima a cero por medio de valores negativos
 * $$\lim_{x \rightarrow 3^+}\frac{x^2+x+2}{x^2-2x-3}=-\infin$$

c)

$$f(x) = \left\{\begin{matrix} \frac {1}{x-2}, & \mbox{si }x \ne 2 \\ 3, & \mbox{si }x = 2 \end{matrix}\right. $$

Se investigan las condiciones

1)g(2)=3 2):$$\lim_{x \rightarrow 2^-}=\lim_{x \rightarrow 2^-}\frac{1}{x-2}$$
 * $$\lim_{x \rightarrow 2^-}=-\infin$$
 * $$\lim_{x \rightarrow 2^-}=\lim_{x \rightarrow 2^-}\frac{1}{x-2}$$
 * $$\lim_{x \rightarrow 2^-}=\infin$$

 * $$\lim_{x \rightarrow 2}g(x)$$ no existe.

title: User:Camilo Acosta


text:
User talk:Camilo Acosta

--Camilo Acosta 14:37, 9 Jul 2004 (UTC)°!"#°"!#"!$

title: User talk:Camilo Acosta


text:
Cookbook:Preparing Yeast

| Bread

This technique is also known as 'blooming'.

Though instant yeasts are now available which can be mixed directly with the dry ingredients in a recipe, many people find that this technique still improves the quality and rising times of bread. Proofing is also the easiest way to determine if an old packet of yeast is still viable.

Ingredients

 * ½ cup (125 ml) of warm water or other liquid reserved from the bread recipe
 * 1 teaspoon of sugar
 * 1 tablespoon of yeast, or as called for in the recipe
 * ¼ teaspoon of ginger (optional)

Procedure

 * 1) Make sure the water is warm and between 112 and 120°F (44 - 49°C). Hot water (above 49C/120F) could kill the yeast, and water above 60C/140F definitely will. Cold water will significantly slow yeast growth. A general guideline is to stick your finger into the water; if you find it warm and comfortable, so will the yeast.
 * 2) Thoroughly stir the ingredients into the water, making sure everything dissolves properly (yeast, in some forms, is rather prone to forming clumps at the bottom). Let this mixture sit in a warm place until there is a bubbly froth on top. Depending on the type of yeast, this will take between 10 and 30 minutes, and should yield a "head" of at least one centimeter. Use as indicated in your recipe. If no bubbles develop, discard and obtain new yeast.

Yeast Cake Substitution
Many older cookbooks will often have recipes calling for a "yeast cake". This is a small cake of active yeast, often 0.6 ounces (17 grams) in weight. They are not normally used today since they are highly perishable and have a short shelf life, even when refrigerated (about 10 days). 1 Yeast Cake can be substituted with 1 packet or 2 1/4 teaspoons of Active Dry Yeast. To substitute a 2 ounce yeast cake, use 3 packets or 6 3/4 teaspoons of Active Dry Yeast.

title: Cookbook:Preparing Yeast


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User:Elian

My main user page is at de:Benutzer:Elian, second most frequented is meta:User:Elian. For messages please use my discussion page on the german wikipedia (write in german, english, french, latin, greek or arabic, first three prefered).

title: User:Elian


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User:Gtrmp

Wikipedia: w:User:gtrmp Meta: meta:User:gtrmp  Wiktionary: Wiktionary:User:Gtrmp

title: User:Gtrmp


text:
Modern Photography/The camera

= Origins of the camera =

Someone's god allegedly said...
"Let there be light!" Most philosophies, religious or otherwise, offer some sort of creation story. Many of these involve light, which for humans, with our highly evolved eyesight, has always been of fundamental importance. People have tried to capture what they have seen for millennia, first with their hands, and then with more advanced technology. Both the traditional arts of painting and sculpture and the modern arts of still and motion photography arose as a result of this drive. The main difference is in the tools, and the primary tool of photography is the camera.

Raw vision
From an evolutionary standpoint, let us suggest for a moment that our first cameras were our eyes. Our evolutionary ancestors used information from their eye-cameras to avoid predators (big scary sabre-toothed tigers) or to find food (colorful fruit falling from trees, for instance). Our brains, by many measures the most sophisticated on the Earth today, spent millions of years evolving extremely well to efficiently process sophisticated images to detect both movement and objects of interest within a still frame. Back in those days, imagery was all about danger, food, and other serious business: the stuff of life that keeps you standing ... or gets you eaten. Incidentally, scientists now know, that when we are born our brains only see random sensory input, they don't have a presupposition that these-nerve-endings-over-here are to do with vision, and those-nerve-endings-over-there are to do with touch. It's all just random input, and in fact in recent years multiple adults have re-trained their brains to receive balance or sight from their tongues.

Primordial aesthetics
Though there was probably very little art in those early times, our aesthetic senses had long since begun to evolve from innate responses to natural stimuli such as commanding views (safety), darkness (danger), light (warmth), and so on. These associations would carry forward in to art as we began to discover ways to record our perceptions of the world: in physical art such as cave paintings, through our sophisticated and relatively unique command of language, and through social modes of communication such as dance and ritual.

Sitting still and going far
Still later, yet far before true cameras appeared, humans used these powers of observation to realise the fundamental principles of light. They knew, for example, that observation of the movement of shadows cast by standing objects over time could be reliably predicted and even associated with the time of day: if you stood at the end of the valley when the shadows had grown long, then you had better run back to the cave or face the evening hunt of the local tigers! This led, as humans began slowly to ponder such mysteries to good effect, to various sorts of technological innovations: chiefly chronological and architectural, but also mathematic, for the line of a shadow is pure and its relationship to the source intrinsic.

Imperfect representation
When copying something, or the image of something, it's usually impossible to do so accurately. This is true fundamentally for the process of depicting our three-dimensional world (four if you count time!) on any two dimensional artwork: including approximately two dimensional cave walls, modern photographs, and early pictures. There are many reasons for this, but perspective is an important factor: our brains cannot perceive depth and therefore anything approaching realism on a flat piece of paper unless given other clues. The first such clue was size, or perspective.

The Grotte Chauvet cave in France includes some of the world's earliest known cave painting, estimated at about 32,000 years old. It is unclear whether these paintings specifically included the device of relative scale, however much of the global body of neolithic art did, ie. the artists sized objects and characters hierarchically according to their spiritual or thematic importance, not their distance from the viewer. It could be argued that theirs was a symbolic perspective, rather than a physical one.

The second such clue was overlapping to suggest relative depth. This was certainly well in use by around the beginning of the common era, with global examples plentiful, for instance in early ancient Egyptian art and Chinese Han Dynasty tombs.

The third such clue was tone. It took humans a great deal of time to comprehend fully the expressiveness of tone for the illusion of depth. Given the relative tonal limitations of naturally occurring rock outcrops and other early media such as pottery, it is perhaps not surprising to realise that the exploration of tone perhaps naturally almost co-incided with the development of that most powerful of mediums: paper! Paper appeared in China at least as early as the early second century BC. According to textual evidence, by the fifth century some of the earliest artwork exploring tones - the layered ink work of the Chinese 山水画 or "mountain and water painting" - had already developed to prominence.

Probably at the same time as the above developments, investigation in to visual perspective began, for instance around the fifth century BC in Greece where the philosophers Anaxagoras and Democritus worked out geometric theories of perspective. Euclid's Optics, a mathematical treatment of perspective, soon followed in around 300 BC.

Then man said...
"Let there be lenses!" Eventually, a distant ancestor of ours had the bright idea of ending all this enjoyable evolutionary fun by discovering naturally occurring crystals that were capable of acting as lenses. Modern evidence of ancient lenses is partial, with some direct finds and some extremely fine workmanship that is held as evidence of lens-work.

In the former category, as recently as the last few years, concepts of ancient navigation in the north Atlantic are being reevaluated following the discovery of formerly near-mythical convex-lens sunstones made from a transparent calcite crystal known as 'Iceland spar' that allowed sailors to determine the direction of the sun even on very cloudy days, and after nightfall in northern latitudes. While the 16th century shipwreck it was found on is fairly late, it is thought to have been an established device by this era, having been referenced in 12th century literature as existing at least as early as the 10th century. The story is compounded by the Visby lenses, a collection of lens-shaped manufactured objects made of rock crystal (quartz) found in several Viking graves on the island of Gotland, Sweden, and dating from the 11th or 12th century. But that's nothing! An 1858 excavation at Niniveh in Babylon also unearthed an ancient Assyrian lens, now known as the Nimrud lens or Layard lens, dating from 750–710 BC, now held in the British Museum and thought to be the oldest in the world.

In the latter category, extremely fine workmanship of a kind considered unattainable with the naked eye (less than 0.1mm) qualifies a 1.3mm wide ivory carving from Abydos, Egypt, recently discovered by German archaeologist Gunter Dreyer that dates from 3300 BC. Other later but still early objects such as the Isopata gold ring from Crete, dated 15th century BC and with workmanship below 0.5mm and approaching 0.1mm and a jasper carving from second century Rome with 0.1-0.2mm details challenge alternate explanation.

Later, a friendly Italian fellow known as Giambattista Della Porta said let there be lenses on cameras! .. or words roughly to that effect. (He was in fact a failed dramatist with a flair for science, blessed with proximity to Venice, a major contemporary center of glass work, who also produced written works on refraction - the bending of light that is the primary science behind basic lens design.)

The coming of the Camera obscura

The lensless camera, camera obscura or pinhole camera, is essentially an opaque box or room with a hole in it. The first surviving mention of some of the principles behind the camera obscura belongs to 墨子 (Mozi; 470-390 BCE), a Chinese philosopher and the founder of Mohism. Mozi correctly asserted that the image in a camera obscura is flipped upside down because light travels in straight lines from its source. His disciples developed this into a minor theory of optics.

In the western world, the camera has been in use in principle since the Renaissance. It was known as the camera obscura, Latin for 'dark chamber', and consisted of a darkened room with a pinhole in the wall facing the subject, which would be outside the room. An inverted image would fall on the opposite wall, which would then be traced manually.

= Cameras =

What is a camera?
At its most basic, a camera is a system for projecting light onto a surface, typically but not exclusively for the purposes of recording the image. This broadest definition includes microsocopes, camera obscura, digital cameras, video cameras (previously known as cine cameras), cell phone cameras and other such devices that are related to conventional cameras but do not necessarily include all of the same features.

Various dictionaries offer a surprising variety of generic but dated definitions for 'camera', most of which predate digital cameras and exclude both lensless devices (pinhole cameras) and video cameras. Here are some examples:
 * Collins English Dictionary (United Kingdom; 2012): an optical device consisting of a lens system set in a light-proof construction inside which a light-sensitive film or plate can be positioned
 * Macquarie Dictionary (Australia; 2014): a photographic apparatus in which a sensitive plate or film is exposed, the image being formed by means of a lens.
 * Merriam-Webster (United States; 2016): a device that consists of a lightproof chamber with an aperture fitted with a lens and a shutter through which the image of an object is projected onto a surface for recording (as on film) or for translation into electrical impulses (as for television broadcast)

The three basic components of a camera are:
 * A device to record the image, which is generally either traditional film or a digital sensor, but can also be various alternative forms of chemical recording surface, glass plates, or similar flat surfaces with the objective of recording an image.
 * A lens that focuses light onto the recording device, and
 * A dark box, or the camera proper, which keeps other light from interfering with the image being recorded.

These three elements may take various forms as required by the type of photography being performed. For instance, the pinhole camera may have a simple opening instead of a lens, and the dark box may in fact be a complex system of flexible, light-tight bellows or a tiny space behind the lens within a cell phone. Also, these basic elements are often accompanied by other equipment, such as shutters and adjustable apertures to control the amount of light entering the camera, viewfinders to aid in selecting and composing the image, as well as lens shades, carrying straps, tripods, etc., that help in creating images with specified characteristic for particular purposes.

Some examples of cameras
Let's look at some examples.
 * In a pinhole camera, one of the simplest types of cameras that it is possible to make, the direction of the image is controlled simply by punching a small hole in the camera box which functions to project an inverted image of the subject on to the surface (eg. recording device) inside.
 * In a view camera, the image is generally captured through a lens (though pinholes can be used) attached to the front of a flexible system of frames and bellows that allows for extensive control of focus and perspective.
 * In a mobile phone camera, a lens is typically fixed in to the device by the manufacturer and emphasis is placed on obtaining maximum utility in a broad range of common personal photographic scenarios, automatic operation, a user-friendly interface, and ease of sharing.
 * In the case of a modern SLR (single lens reflex) or DSLR (digital SLR) camera, the image is almost always a captured through a glass lens, using a precise shutter to control the length of exposure.

Today, when we discuss cameras we are almost always discussing modern cameras, those incorporating an opaque camera body, precise shutter speed and aperture control, and a proper lens.

Five basic controls
As the purpose of a camera is to project light onto a surface that will record an image, most cameras have the same basic controls and these controls affect how the image is recorded. These five basic controls are:

 * Location and orientation of the camera: The most basic variables you can alter, and perhaps the most important. While distance from some subjects may sometimes be an asset (wildlife, covert photography, capturing natural expressions during event photography), often getting in close to a human social distance offers the most engaging angles. Similarly, shots from far above or below can lend incredibly different feelings to the subject, and suggest different reactions to the viewer. Generally, shots from far above may inspire feelings of safety or distance from the subject, encouraging the subject to be considered in a more distant or philosophical mindset by the viewer. Shots from below may make the subject appear large and dominating, exaggerating its presence.
 * Focus: All but the simplest cameras allow the photographer to select the distance at which the image is the sharpest, or its "focus". This can take various forms, from manually turning a ring on a lens to bring the image into focus, to simply pointing to an object on a mobile phone's screen to select the corresponding distance automatically. In conjunction with the aperture setting below determines which objects in the final image will be sharp, and which blurry.
 * Shutter speed ("how long the image is exposed for"): The amount of time that light will be allowed to pass through the lens during the exposure (ie. between the beginning and the end of the photograph). The longer the shutter is open, the brighter an image will become, however the image will also be more sensitive to motion blur as a result of movement in the camera or the subject it is capturing. Sports or action photography therefore depends upon fast shutter speeds (ie. shorter exposures), whereas careful and slow photography of relatively dark or still subjects (mountains, stars in the sky, etc.) generally depends upon slower shutter speeds.
 * Aperture ("how big the hole is"): The size of the (usually roughly circular) opening behind the lens. A larger aperture (or opening) will allow more light to pass through the lens than a smaller one. A larger opening will create a brighter image, but the depth of focus (or "depth of field") becomes shallower, allowing fewer objects to remain sharp in the image. Correspondingly, small openings allow subjects within a greater range of distances from the camera to be crisply delineated, but allow less light in and therefore require longer shutter speeds for proper exposure. Many photographers use this to great artistic advantage by either bringing the image into crisp focus or just the opposite, focusing on a single element and letting the rest of the image blur out so as not to distract the viewer's attention. Apertures are measured in 'f-stops', which are written number. Note that these numbers are 'backwards': since they are fractions of the lens focal length, noted as "f", smaller numbers such as 0.95) mean bigger openings and more light entering the camera, whereas larger numbers (such as 6.3) mean smaller openings and less light.
 * Sensitivity ("how fast the image is recorded") (often when expressed casually, ISO, which actually refers to the ISO 5800 standards documents originally published for film speed by the International Organization for Standardization): In any event, the sensitivity of the film or digital sensor to light. In traditional film cameras, you had to swap film to change this factor because it was a property of the type of film being used. In modern digital cameras, the ISO rating describes film-speed equivalency and is almost always possible to change in the camera, either manually or automatically. The scale is arithmetic, which means that a film with a rating of ISO 800, for example, will be eight times more sensitive to light than one of ISO 100. A higher ISO is useful in low light environments, however increasing the ISO will affect the quality of the image: in film the images become grainy, and in digital the image becomes noisier, with more undesirable speckles. Some of these noise articles can be removed after the fact, however, and low light performance is an area in which digital sensors have been making rapid improvements in recent years.

Changing any of the settings will affect how the image looks and will be discussed further later. For now let's briefly examine some additional controls available to photographers, then look at different cameras and where these controls can be found.

Additional controls
In addition to the basic controls of shutter speed, aperture and sensitivity, some cameras provide or may be fitted with additional controls, including:
 * Lens and zoom selection: Many cameras allow you to change lenses to achieve different optical effects, predominantly related to depth of field, minimum focal distance, what percentage of a scene will be captured within the frame, available light (faster lenses provide mode light) and whether or not zoom is possible to adjust without changing lenses again.
 * Tilt/shift or lens/image plane alignment. Built in to some types of cameras, particularly old analog view cameras, but available as aftermarket lens features even on modern DSLR camera systems, such controls enable the photographer to carefully manage which portions of a subject remain in focus and distort or correct their perspective optically, prior to recording of the image.
 * Lighting: Many cameras have built-in or optional 'flash' lighting. In addition, some cameras allow external lights to be connected by wire or wireless. Careful control of the lighting in a scene is most often made in studio photography, such as portraiture, still life and commercial product and advertising photography.
 * Optical filters have long been used by photographers to achieve additional control of their images. There are many types available:
 * Polarization (control of light wave orientation and therefore reduction of overall light entering the camera; these are further divided in to circular and linear polarization filters - the former are more expensive and are designed to allow modern camera metering and auto-focus systems to continue to function normally)
 * Wavelength (for instance infra-red or ultra-violet wavelength filters may block these specific wavelengths, and individual colour filters may for example block blues, reds or greens. There are also warmth filters that enhance or reduce a broad range of colors over a greater breadth of the visible spectrum simultaneously, for example with the objective of countering the unnatural colour effects of certain types of artificial lights such as fluorescent bulbs.)
 * Neutral density (blocking all wavelengths of light equally but only partially, in order to effect slower exposures of the same scene, for example to accentuate motion blur in moving subjects such as running water. These may be complete or graduated, ie. blocking more light on one side of the image than another, often in a clean gradient.)
 * Blur, softening or diffusion (reducing focus from certain portions of an image, often to create a dream-like effect)
 * Diopter, close-up or macro (allows a given lens to focus closer to a subject than it is usually capable)
 * Bokeh (apply specific geometric shapes to the brightest portions of the bokeh - or highly unfocused image regions)
 * Novelty (the classic example are star filters, which alter highly directional lights - also known as point lights - to obtain a cheesy, starry, visual effect; another example are also multivision filters which can provide multiple copies of the subject within the frame. Such filters are generally remnants of the analog era and are now being replaced by software post-processing.)
 * Compound imaging modes are modes in which multiple exposures may be combined in to a single image. There are two main types of compound imaging:
 * Multiple exposure is a classic analog-era technique in which two or more exposures are made to the same piece of film, often resulting in a dream-like tangle of tones or surreal combinations of subjects.
 * High Dynamic Range (HDR) images may be produced in the digital-era by either manual or automated exposure bracketing, a process in which multiple exposures are taken of the same subject with different shutter speeds. These higher and lower exposures are then combined in to a single image, enhancing the effective dynamic range of the image (ie. capturing a broader range of shadow and highlight detail than would otherwise be possible). Some cameras have this feature built-in, others allow the automation of capture but leave the combination of the multiple resulting images to computer-based post-processing.
 * Digital-only controls' are those which are artifacts of the era of digital photography.
 * Effects are pre-built options on digital cameras allowing for certain types of post-processing within the camera itself. While these may be set before taking an image, much like the basic controls, they are in fact generally only applied by the camera in software after the image has already been captured, and thus are not true image-taking controls.
 * Color depth is the amount of information to be stored for each individual pixel (square) of a digital image. It may be expressed in two ways, either:
 * For each color-channel (red, green and blue), or 'bits per channel'. This is the standard means of description in the photographic world.
 * In terms of the total 'bits per pixel' (combining all colour channels), which is a common means of description in the computer imaging world.
 * For example, an 8 bit color depth per channel image would have 24 bits per pixel, a 16 bit color depth per channel image would have 48 bits per pixel, and so on. Modern digital image sensors provide at least 16 or 24 bits per channel, though 8 bits per channel is still adequate quality for many purposes and is very common online.
 * Resolution is the amount of pixels (square, component points within an image) to store when taking a photograph. Higher resolution generally creates a higher quality image, though poor lenses, motion or subject blur, long exposures or a constrained publishing resolution may all provide good reasons to reduce resolution at the time of capture. Reducing resolution increases camera image storage speed (increasing the number of images per second that may be stored, for example in burst mode photography of action such as sporting events) as well as overall storage space requirements, image transmission times, etc. It is generally expressed in pixels as width x height, though some cameras provide a simplified set of options based on the conventions "RAW, LARGE, MEDIUM, SMALL" and many support the dual storage of both RAW and processed raster files (usually JPEG) of a selected size.

Types of cameras
The following terms have been historically used to describe various types of still cameras. These terms are not entirely exclusive (for example, you can have a Single lens reflex or twin lens reflex pinhole studio camera), nor are they necessarily the only terms around. They are included here for reference purposes.

Consumer/Prosumer
Consumer cameras are mass produced, mass market cameras designed for a broad range of common use by the general public. Once a significantly distinct form of camera from professional cameras, the combination of the popularization of digital camera technology and the rise of the 'prosumer' (ie. high end consumer) concept has tended to erode the distinction between professional and consumer cameras. In reality, many modern consumer/prosumer cameras are essentially capable of professional output.

Professional
Professional camera systems are essentially those not positioned for consumer use. This category includes expensive or specialist cameras utilized for artistic, industrial, or studio uses.

Industrial
Industrial cameras are those engineered for repeat utilization, generally as a part of a larger, automated, electronic system. This may include applications such as manufacturing quality control, satellite telescopes, microscopy, or surveillance. In general, industrial applications place a greater emphasis on reliability and a reduced emphasis on breadth of application. They may require extensive knowledge of physics, observed processes or optics to initially configure. They tend to be relatively expensive.

Studio
Studio cameras are those optimized for non-mobile applications. Once a relatively separate category of camera, today most studios utilize professional SLR cameras from major manufacturers which may incorporate connections to studio lighting (eg. flash rigs, reflectors) and positioning equipment (eg. tripods), so this term is perhaps falling out of use.

Pinhole
The pinhole camera is relatively rare today, but is enjoying a resurgence of casual interest due to its simplicity. It is one of the simplest camera designs possible and has three major components: a light-proof box, a light sensitive material (such as a traditional analog film, or a digital sensor) and opposite the material a hole that light passes through carrying the external image. There is no lens; the aperture is created by punching a small hole opposite where the film is mounted and is very small; and the 'shutter' in more advanced cameras is emulated manually by uncovering and covering the opening. Despite its simplicity, it still has many enthusiasts because of the unique pictures it creates and the imaginative ways of turning ordinary objects into pinhole cameras.

Analog pinhole cameras are very easy to make from scratch for exposing traditional film: the principle is identical to the pioneering camera obscura experiment. Typically, a prefabricated, light-sealed container like a biscuit tin or a match-box can be used. Most digital cameras with changeable lenses can be converted in to pinhole cameras by replacing the lens with a sheet of opaque material with a hole punched in it.

Note that a method exists for calculating the optimum pinhole size: too small or too large and the image will lack definition.

Fixed lens
These include most "point-and-shoot" cameras. While the lens on these cameras is not removeable, the focus is often adjustable, whether manually or automatically. These cameras are generally not considered high quality equipment, though several outliers, such as the Rollei 35 are prized for their high-grade optics.

Interchangeable lens
Most cameras for professional or advanced amateur use today have the ability to change lenses, depending on the photographer's need. The need for this is largely mooted by the advent of zoom lenses with adjustable focal lengths, but more advanced applications may still require the use of a specialized lens.

By focal method
Focus is fundamental to photography, a fact that has determined the development of the different broad types of camera. Focus is dependent upon a number of relationships, distance of the subject from the camera being the most important.

No focus
Some cameras do not offer the photographer any means to adjust focus. These cameras would typically be of the following types: Today these cameras are usually made to simplify construction and lower costs, especially for applications where the subject-to-camera distance is likely to remain constant, such as fixed security cameras or in some technical applications. For general photography applications they are of only passing interest, though a number of artists have worked with them to great effect.
 * Very simple (lensless), such as pinhole cameras
 * Very early, simple or less sophisticated amateur cameras, from the early development of modern photography
 * Non-interchangeable, simple, fixed prime lens special purpose cameras (for example, certain early analog spy cameras or those designed to be operated from aerial balloons)

Fully manual focus
Many field or view cameras (the sorts of things you see people taking photographs under blankets with in early 20th century or late 19th century movies, and their spiritual successors) provide no automated means for focusing, instead relying on the photographer to manually adjust the focal ring on the lens based upon comparing an estimate distance to numbers marked or engraved there for that purpose. Eventually, separate devices for estimating subject distance became available, known as rangefinders.

Rangefinder cameras
Prior to the widespread development of electronic autofocus systems, the dominant focusing technique of the late 20th century was the analog rangefinder, sometimes shortened to RF. In the most common configuration of such a system, the photographer manually aligns two images within a viewport. Once the images are aligned, the camera is said to be in focus, and a subject distance may be displayed or derived. Earlier and cheaper systems including the initial, portable, off-camera systems required the photographer to manually transfer the resulting distance to the configuration of the focus ring on their camera, which would be marked with various distances in feet or meters. Later systems, such as those still produced by companies such as the German manufacturer Leica Camera AG, couple the results to the focusing mechanism of the camera and are known as coupled rangefinder cameras.

Historically, the major advantages of the rangefinder designs are for certain applications. Since there is no moving mirror, as used in SLRs, there is no momentary blackout of the subject being photographed. The camera is therefore often quieter, particularly with leaf shutters, and usually smaller and less obtrusive. These qualities make rangefinders more attractive for theater photography, some portrait photography, candid and street photography, and any application where an SLR is too large or obtrusive. The absence of a mirror allows the rear element of lenses to project deep into the camera body, making high-quality wide-angle lenses easier to design. However, it is important to note that these advantages are now shared by many types of digital cameras and cellphones, which usually do not require manual focus or exposure: for example, 'silent mode' on the Sony α7R II.

Autofocus (AF)
The majority of camera systems today provide some means of electronic autofocus (AF), though there are still other camera types produced. Electronic autofocus systems are very complex and can provide unrivaled support for certain photographic situations, for example: Autofocus systems are based upon various technologies, a current example of which is 'phase-difference', presently in use (2016) by high-end Canon DSLRs such as the 50.4 Megapixel Canon 5DS.
 * Action telephoto photography with occasional intermediate obstructions
 * Normally moving subjects such as sports people running or walking
 * Highly erratically moving subjects, such as darting animals or insects

Twin lens reflex
The exact origins of the twin lens reflex (TLR) camera are obscure. Double-lens cameras were around from about 1870, when someone realised that having a second viewing lens alongside the taking lens meant that one could focus without having to keep swapping a ground glass screen for the plate afterwards, reducing the time delay in actually taking the shot.

Where the TLR came into its own was with the idea of using a reflex mirror to allow viewing from above, thus allowing the camera to be held much more steadily if handheld. The same principle of course applied to the single lens reflex, but early SLRs caused delays and inconvenience through the need to move the mirror out of the focal plane to allow light to the plate behind it. When this process was automated, the movement of the mirror could cause shake in the camera and blur the shot.

One of the earliest documented TLRs was made by the firm of R & J Beck of Cornhill, London in 1880 for Mr G M Whipple, a scientist and Superintendent of the Royal Observatory at Kew. It seems the design concept was his - to build a mirror reflex camera for cloud photography. The aim was to have a camera with lenses pointing upwards, but also to be able to compose the picture whilst looking horizontally. It seems this camera also used geared linking to synchronise the lenses, thus having many of the features of later mass-marketed TLRs.

There were a number of other types of TLR marketed between about 1890 and 1910, but these were gradually overtaken as more effective SLRs became available and cured the problem of parallax which bedevilled the TLR. The ability to see and compose the subject exactly in the taking lens outweighed the disadvantage of the moving mirror as SLR mechanisms improved.

Single lens reflex
As already discussed, focus is fundamental to photography, both in terms of what is and what is not in focus. A rangefinder camera, which allows one to determine the focusing distance, determines what should be in focus, but without actually demonstrating the degree. The TLR (Twin-Lens Reflex camera) goes one step further, by using a second viewing lens.

However, it is the SLR (Single Lens Reflex camera) that solves the problem fully. In this type of camera a mirror intercepts the light that passes through the lens and projects it onto a ground glass screen where it forms an erect (upright) but mirrored image. Now the photographer is truly viewing through the lens and able to accurately determine both the focus and depth of field. When the photograph is ready to be taken the mirror is retracted allowing the light to pass directly to the film, when the shutter is opened. The earliest models required the mirror to be retracted manually (this disappeared with the Speed Reflex in the mid-1920s), did not have the familiar prism of today, and demanded the viewer to inspect the image through a leather tlunnel to the ground glass screen. Another common feature of SLRs necessitated by their construction was the need for the light to pass through the lens to the reflex mirror unhindered. This lead to the focal plane shutter, where the mechanism is placed just in front of the film.

This is how most people perceive the SLR with the distinctive prism housing on top that first appeared on a Contax camera in 1948. The prism serves to reflect and flip the mirrored image from the ground glass screen to the viewfinder, resulting in an erect and true image which is bright and often magnified by the viewfinder optics. The use of 35mm film allows these cameras to be relatively compact which removed one of the SLRs drawbacks. With the shutter positioned just ahead of the film within the camera's body, it is possible to change lenses without exposing the film, making the design very flexible. The principal shortcoming is that the focal plane shutter uses a variable gap to vary the shutter speed and that only a longish exposure time will synchronise with flash.

View camera
The view camera is of either a monorail design or what is called a flat bed or field camera. The flat bed being an older design and dating back to the middle of the 19th century. In both designs a flexible bellows separates the lens and film. The lens is affixed to a front standard and the film positioned in the rear standard. Both front and rear standards can move horizontally along the rail of a monorail or on tracks in the bed in the case of the flatbed design. In most designs the front and rear standards are equipped to pivot in both the x and y axis independent of each other. These are called "swings" and "tilts". There is usually some allowance for the rise and fall of both front and rear standards along the vertical plane. All of these movements allows for great flexibility in the control of the image.

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title: Modern Photography/The camera