Question

integral cos^3(x)dx

Answer 1

cos^2 x = 1 - sin^2 x hence
\[ \int \cos^3 x \ dx = \int (\cos x - \sin^2 x \cos x) \ dx \]

and hopefully now that 's an integral you can do.

Answer 2

then we just use u sub, thanks

Answer 3

or do we?

Answer 4

for the integral of cos x dx, no.

for the integral of sin^2 x . cos x dx, yes.