How do you integrate cosx(sinx)12dx?

1 Answer
Jan 2, 2016

cosx(sinx)12dx=2(sinx)12+C

Explanation:

Let's try to guess what was derived.

We could notice, that:
ddxsinx=cosx and ddx(f(x)12)=ddxf(x)2f(x)12 (chain rule)

So we try to substitute u=sinx:
du=cosxdx

cosx(sinx)12dx=duu12=2du2u12=2u12+C

We need to substitute u=sinx back:

2u12+C=2(sinx)12+C

Please tell if you need more explanation.