mathmatics and functions

This is a discussion on mathmatics and functions within the A Brief History of Cprogramming.com forums, part of the Community Boards category; if I'm defining the range of a function would the following be valid documentation? Function and rule: f(x)=x^2 Range f(x) ...

  1. #1
    essence of digital xddxogm3's Avatar
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    mathmatics and functions

    if I'm defining the range of a function would the following be valid documentation?

    Function and rule:

    f(x)=x^2

    Range f(x) = {f(x)|f(x)>=0}

    or is it better to write the range similar to the following.

    since,

    f(x)=y

    then,

    Range f(x) = {y|y>=0}

    My question is just which is the preferred method of documentation of the mathematician world?
    "Hence to fight and conquer in all your battles is not supreme excellence;
    supreme excellence consists in breaking the enemy's resistance without fighting."
    Art of War Sun Tzu

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    former member Brain Cell's Avatar
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    *EDITED OUT*
    Last edited by Brain Cell; 10-09-2004 at 06:48 PM.
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    Toaster Zach L.'s Avatar
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    This fits in general chat.
    There are many ways of denoting the range in mathematics. Which one is favored really depends on the branch of mathematics (not all sets that you would want to map a function into have the string ordering, <, or the weak ordering, <=, for example), and on personal preference. I'd be inclined to favor the first version you posted.
    The word rap as it applies to music is the result of a peculiar phonological rule which has stripped the word of its initial voiceless velar stop.

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    former member Brain Cell's Avatar
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    sorry me im REALLY sleepy and i think i misread his post lol. I'll go to sleep before i cause more troubles
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    Toaster Zach L.'s Avatar
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    Haha... Sleep? What is this you speak of?
    The word rap as it applies to music is the result of a peculiar phonological rule which has stripped the word of its initial voiceless velar stop.

  6. #6
    essence of digital xddxogm3's Avatar
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    thank you.
    sorry if my question isn't to clear.
    I know two languages.
    My native tounge is bad english, but I have been know to talk in a newer dialect called worst english.
    ;0)
    "Hence to fight and conquer in all your battles is not supreme excellence;
    supreme excellence consists in breaking the enemy's resistance without fighting."
    Art of War Sun Tzu

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    S Sang-drax's Avatar
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    Of those two notations, I'd prefer the second one.
    Last edited by Sang-drax : Tomorrow at 02:21 AM. Reason: Time travelling

  8. #8
    essence of digital xddxogm3's Avatar
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    so are you people just trying to confuse me because of the new homework post?
    I thought my questions on mathmatics have been very clear, and do not ask for you to do the homework for me. now i'm confused, if this is asking to much or violating the homework rule could someone tell me. I do believe both would be technically correct, but the usage would probably be personal preferrence.
    "Hence to fight and conquer in all your battles is not supreme excellence;
    supreme excellence consists in breaking the enemy's resistance without fighting."
    Art of War Sun Tzu

  9. #9
    S Sang-drax's Avatar
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    I think the first notation looks very strange. If you want to use f(x), just write:
    {f(x)|x€R}
    {x^2|x€R}
    or
    f(x)>=0
    Because range(f) is every possible value of f.
    Last edited by Sang-drax : Tomorrow at 02:21 AM. Reason: Time travelling

  10. #10
    Toaster Zach L.'s Avatar
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    I'd be more likely to write something like:
    f >= 0 (where the variable is implicit)... but that's just me.

    Use which ever notation you prefer (or, which ever one your teacher prefers ).
    The word rap as it applies to music is the result of a peculiar phonological rule which has stripped the word of its initial voiceless velar stop.

  11. #11
    essence of digital xddxogm3's Avatar
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    Sang-drax
    how did you get the element symbol? is that a currency format?
    {f(x)|x€R}
    {x^2|x€R}
    thanks for everyones input on this question.
    i will be asking my teacher how she wants the answer.
    i was just wondering if there was an unstated rule on what was an accepted format among the mathematicians. I feel my question was answered in detail.
    "Hence to fight and conquer in all your battles is not supreme excellence;
    supreme excellence consists in breaking the enemy's resistance without fighting."
    Art of War Sun Tzu

  12. #12
    S Sang-drax's Avatar
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    Quote Originally Posted by xviddivxoggmp3
    Sang-drax
    how did you get the element symbol? is that a currency format
    The Euro is good for many things, not just for free trade within Europe etc.
    on European keyboards with Windows, the euro symbol is typed with Alt Gr+E.
    Last edited by Sang-drax : Tomorrow at 02:21 AM. Reason: Time travelling

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