SOLUTION: Evaluate {{{int((x/(1+cos^2(x))), dx, 0, pi)}}}, and please give detailed solution.

Algebra ->  Surface-area -> SOLUTION: Evaluate {{{int((x/(1+cos^2(x))), dx, 0, pi)}}}, and please give detailed solution.      Log On


   

Question 1027913: Evaluate int%28%28x%2F%281%2Bcos%5E2%28x%29%29%29%2C+dx%2C+0%2C+pi%29, and please give detailed solution.
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!

by using the identity %281%2Bcos2x%29%2F2+=+cos%5E2%28x%29.
Now let x+=+pi+-+y and substitute into the second integral.
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Now , by letting 3+=++3sin%5E2%28x%29+%2B+3cos%5E2%28x%29 and cos2x+=+cos%5E2%28x%29+-+sin%5E2%28x%29.
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