SOLUTION: Prove: (12tan a)/ (1+tan^2 a) = 6sin 2a

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Question 1161414: Prove:
(12tan a)/ (1+tan^2 a) = 6sin 2a
Answer by Edwin McCravy(20064) About Me  (Show Source):
You can put this solution on YOUR website!
%2812tan%5E%22%22%28a%29%29%2F+%281%2Btan%5E2%28a%29%29+=+6sin%5E%22%22%282a%29

We work with the left side:







Get LCD on the right:





      Use the identity: cos²θ+sin²θ=1 



To divide by a fraction, we invert and multiply:



Cancel:



12sin%5E%22%22%28a%29cos%5E%22%22%28a%29

6%282sin%5E%22%22%28a%29cos%5E%22%22%28a%29%5E%22%22%29

6sin%5E%22%22%282a%29

Edwin