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    Can anyone help? Been stuck for a while...
    Thanks!

    Prove the identity sinx+cosx=(1-2cos^2x)/(sinx-cosx)
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    (Original post by DonHorizon)
    Can anyone help? Been stuck for a while...
    Thanks!

    Prove the identity sinx+cosx=(1-2cos^2x)/(sinx-cosx)
    Start from the RHS, try using cos^2x=1-sin^2x
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    (Original post by NotNotBatman)
    Start from the RHS, try using cos^2x=1-sin^2x
    Thanks! That's what I tried to do at first but I just can't seem to get it to work!
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    (Original post by DonHorizon)
    Thanks! That's what I tried to do at first but I just can't seem to get it to work!
    Could you show what you have done?
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    (Original post by NotNotBatman)
    Could you show what you have done?
    I got into a position where I had 2sin^2x-1/sinx-cosx
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    (Original post by DonHorizon)
    I got into a position where I had 2sin^2x-1/sinx-cosx
    try to get (sin^2x - cos^2x) on the top
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    (Original post by DonHorizon)
    I got into a position where I had 2sin^2x-1/sinx-cosx
    Okay, I've just jotted it down. Easiest way to do it is to start from the RHS and use 1 = cos^2x+sin^2x , then it's straightforward from there.
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    (Original post by NotNotBatman)
    Okay, I've just jotted it down. Easiest way to do it is to start from the RHS and use 1 = cos^2x+sin^2x , then it's straightforward from there.
    Ahh! I've done it now! Thanks so much!
 
 
 
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