- #1
flyingpig
- 2,579
- 1
Homework Statement
[tex]\int \;\sinh(2x) \cosh(2x) dx[/tex]The Attempt at a Solution
I let u = sinh(2x), du = 2cosh(2x)dx
Integrating I shuold get[tex]\frac{1}{4} sinh^2 (2x) + C[/tex]
But http://www.wolframalpha.com/input/?i=Integrate[cosh%282x%29%28sinh%282x%29%29%2Cx]
says I need to let u = 2x first. Why? I don't think i am wrong, my algebra looked correct.