Given that the total cost function for x units of a commodity is : $C(x)=\large \frac{x^3}{3}\normalsize +3x^2-7x+16$

Question

(i) Find the Marginal Cost (MC) (ii) Find the Average Cost (AC) (iii) Prove that : Marginal Average Cost (MAC)=$\large\frac{x(MC)-C(x)}{x^2}$