Christopher F. answered 04/10/20
M.S. in Mathematics with 500+ hours in Calculus tutoring
First, let's find F'(x):
F'(x) = 3x2 ----> F'(a) = 3a2 = 3(12) = 36
Now, let's find G'(x):
G'(x) = 3(f(x))2f'(x), by chain rule. ----> G'(a) = 3(f(a))2f'(a) = 3(2)2(15) = 3(4)(15) = 3(60) = 180