Evaluate the intgral of cos^5 x dx

[nikchic5]

Can someone please help me do this? Thanks so much!

The integral of cos^5 x dx

Thanks so much for any help!!

 

[morson]

\(\displaystyle \L\ = \int cos(x) cos^4(x) \ dx = \int cos(x) (1 - sin^2(x))^2 \ dx\)

Now put \(\displaystyle u = sin(x)\) and see where it takes you.