find f '(-4) with given equation

Question

Find f '(-4), if f(x) = (5x² + 6x)(3x² + 7). Round your answer to the nearest integer.

Answer 1

It might be easier to expand f(x) into 15x^4 + 18x^3 + 35x^2 + 42x;

then f'(x) = 60x^3 + 54x^2 + 70x + 42

so f'(-4) = -3,214

Judging from your previous problem on the quotient rule, you might have preferred to use the product rule in this case,