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Math Help - Basic Cosine

  1. #1
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    Basic Cosine

    Im having a brain fade here, and I know this is basic algebra, but cant remember how to do it. I need to solve for cos(theta)

    1-cos(theta)=1+cos(theta)

    Thanks for your help
    Last edited by mr fantastic; December 8th 2009 at 12:56 PM. Reason: rt --> de
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  2. #2
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    Quote Originally Posted by BCHurricane89 View Post
    Im having a brain fade here, and I know this is basic algebra, but cant remember how to do it. I need to solve for cos(theta)

    1-cos(theta)=1+cos(theta)

    Thanks for your help
    Add cos(\theta) to both sides and then add -1 to both sides:

    2cos(\theta) = 0

    \theta = \frac{\pi}{2} \pm k\pi where k is an integer
    Last edited by mr fantastic; December 8th 2009 at 12:56 PM.
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  3. #3
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    doh! that kinda what I thought, except the book had cos(theta)=0, but we have 2cos(theta)=0
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