## Calculus (3rd Edition)

Apply the product rule: $F'(x)=f(x)\frac{d}{dx}(x^{2})+x^{2}\times f'(x)$ $=f(x)\times2x+x^{2}\times f'(x)$ $F'(4)=f(4)\times2(4)+(4)^{2}\times f'(4)$ $=(10\times8)+(16\times-2)=48$