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Math Help - Proving Identities

  1. #1
    Junior Member
    Joined
    Jan 2010
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    60

    Proving Identities

    I have to prove the following identity, and i'm not understanding this question

    sin2x / 1-cos2x =cotx

    not sure if i did that right, sin2x is the numerator and 1-cosx is the denominator and they have to equal cotx

    Thank you
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  2. #2
    Member
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    Oct 2009
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    Expand \sin 2x and \cos 2x using the double angle identities and use the fact that 1-\cos ^2 x = \sin^2 x The answer follows trivially.
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  3. #3
    Junior Member
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    Jan 2010
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    Right, i forgot about the double angle identities, thank you so much
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