I think I know how to differentiate it, this is what I did:
f(x)=cos^2(sinx)
f'(x)=[(2)(cos)(-sin)(sinx)](cosx)
and the answer is:
=-2cos(sinx)[sin(sinx)](cosx)
Why are there so many brackets being used in the answer? Couldn't I have went from my step 2 to:
=-2cos(sinx)sin(sinx)(cosx)?