For each of the given functions f(a), find the derivative (f.]) (c) at the given point c, first finding a = f-(c). a) f(x) = 4x + 7x23; c = -11 Q = (f-1 ) ' (c ) =1 b) f(x) = x2 - 16x + 76 on the interval [8, co); c = 16 a = ( f - 1 ) ( c ) =