Suppose h = f○g. Find h'(0) given that f(0) = 8, f '(3) = -4, g(0) = 3, and g '(0) = 9.


I understand that the derivative of h is as follows

h'(x)=f(g')+g(f')

therefore

h'(0)= 8(9)+3(f')

but I can not figure out how to find f'