How do I solve this?

4. (2+2=4 marks/ Let /(x) = rsin (x). Suppose also that h and & are defined as follow: h'(x) = cos (n sin(x)) k'(x) = f(x + 27) h(0) = k(0) = 0 Find (a) [2 marks) (f oh)'(0) (b) [2 marks) (ko f)' ()