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Math Help - Trigonemetry Graphs

  1. #1
    Bar0n janvdl's Avatar
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    Trigonemetry Graphs

    I got a Sin and Tan Graph.

    The sin graph's formula: y = a sin x
    The tan graph's formula: y = tan 1/a x

    These two graphs cross at 120 degrees.

    So that means:
    a sin 120 = tan 1/a 120

    But how can i find the value of a? Somewhere im missing something.
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by janvdl View Post
    I got a Sin and Tan Graph.

    The sin graph's formula: y = a sin x
    The tan graph's formula: y = tan 1/a x

    These two graphs cross at 120 degrees.

    So that means:
    a sin 120 = tan 1/a 120

    But how can i find the value of a? Somewhere im missing something.
    a=+/-2

    How did I find these solutions - educated guess and check

    OK really - use a numerical method which suggested that 2 might be a root,
    checking proved that this was indeed the case, then symettry suggest -2
    is also a root. Then there is some very nasty behaviour for small a which
    I will have to think about.

    RonL
    Last edited by CaptainBlack; May 9th 2007 at 09:52 AM.
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  3. #3
    Bar0n janvdl's Avatar
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    Quote Originally Posted by CaptainBlack View Post
    a=+/-2 +n*pi for n=0, +/-1, ...

    RonL
    Sorry, i saw only now you said you guessed.

    So theres no way of calculating this???
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  4. #4
    Bar0n janvdl's Avatar
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    Why is "a" so very nasty? I mean, for goodness' sake i'm only in matric, not varsity.
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  5. #5
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    Off topic sorry.

    Is matric/varsity a High School/College/Uni ?
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  6. #6
    Bar0n janvdl's Avatar
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    Matric is the highest grade of high school.
    Varsity means university.

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  7. #7
    Grand Panjandrum
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    Quote Originally Posted by janvdl View Post
    Why is "a" so very nasty? I mean, for goodness' sake i'm only in matric, not varsity.
    If you have something suitable try plotting

    y=x sin(120) - tan(120/x)

    for x=0.00001 to 1.

    RonL
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