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Thread: rearanging trig equation

  1. #1
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    rearanging trig equation

    0.04=0.08cos(12.57t)

    arccos(0.04/0.08)/12.57=t

    t=4.77

    is this correct?
    If yes, why the solution on the book is t=0.083?

    Thanks in advance
    Last edited by cxz7410123; Jan 15th 2017 at 02:34 PM.
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  2. #2
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    Re: rearanging trig equation

    Quote Originally Posted by cxz7410123 View Post
    0.04=0.08cos(12.57t)
    cos(12.57t) = 1/2
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  3. #3
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    Re: rearanging trig equation

    Quote Originally Posted by cxz7410123 View Post
    0.04=0.08cos(12.57t)
    is this correct?
    If yes, why the solution on the book is t=0.083?
    See HERE.
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  4. #4
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    Re: rearanging trig equation

    Quote Originally Posted by cxz7410123 View Post
    0.04=0.08cos(12.57t)

    arccos(0.04/0.08)/12.57=t

    t=4.77

    is this correct?
    If yes, why the solution on the book is t=0.083?
    change your calculator from degree to radian mode ...
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  5. #5
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    Re: rearanging trig equation

    $0.04=0.08\,\cos(12.57t)$

    $\dfrac{0.04}{0.08}=\cos(12.57t)$


    $\dfrac{1}{2}=\cos(12.57t)$

    $\cos^{-1}\dfrac{1}{2}=(12.57t)$


    $60\times\dfrac{\pi}{180}=(12.57t)$

    $1.047=12.57t$

    $t=0.083$
    Last edited by deesuwalka; Jan 16th 2017 at 12:43 AM.
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