SOLUTION: Prove the identity: cot(^2)x-1 / cot(^2)x+1 = cos2x

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Question 982592: Prove the identity:
cot(^2)x-1 / cot(^2)x+1 = cos2x
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
cot(^2)x-1 / cot(^2)x+1 = cos2x
%28cot%5E2%28x%29-1%29%2F%28cot%5E2%28x%29%2B1%29
cot%5E2%28x%29%2B1=coec%5E2%28x%29
%28cot%5E2%28x%29-1%29%2F%28cosec%5E2%28x%29%29
%28cot%5E2%28x%29%2Fcosec%5E2%28x%29%29-%281%2Fcosc%5E2%28x%29%29

cos%5E2%28x%29-sin%5E2%28x%29
cos(2x)