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Math Help - Proof Help!?

  1. #1
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    Unhappy Proof Help!?

    I have been stuck on this proof for a while, i know all the identities and think i am either really close and cant see it or my algebra is wrong.
    (1-tan^2x)/(1+tan^2x)=1-2sin^2x
    i have tried it from many angles, so far the only thing i am sure i did correct was
    numerator: (sin^2+cos^2)-(sin^2/cos^2)
    denominator: (sin^2+cos^2)+(sin^2/cos^2)
    Thanks for any help in advance.
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  2. #2
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    Re: Proof Help!?

    Quote Originally Posted by johnreal View Post
    I have been stuck on this proof for a while, i know all the identities and think i am either really close and cant see it or my algebra is wrong.
    (1-tan^2x)/(1+tan^2x)=1-2sin^2x
    \frac{{1 - {{\tan }^2}(x)}}{{1 + {{\tan }^2}(x)}} = \frac{{{{\cos }^2}(x) - {{\sin }^2}(x)}}{{{{\cos }^2}(x) + {{\sin }^2}(x)}}
    Thanks from johnreal
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  3. #3
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    Re: Proof Help!?

    Thanks i see how i would get the answer from there, i saw my algebra mistake when using the fractions, BTW cool name.
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