\fIf u is a function of x, and n is a positive integer, then a (u)" = n . (u)"-i. d (u) or f'(x) = ng(x)]"-1.8'(x) dx dx Eg.3: a) Find the value of dy for x = -2 if y = x4(3x +7)3 dx b) Find the value of for x = -lif y = (2x +1) . (3x+2)4 dxIn words this is the derivative of the top times the bottom minus the derivative of the bottom times the top, all over the bottom squared. Proof: x We want to nd h'(x), given that [1(x) = % g(x) are 0. We rewrite this as a product: h(x)g(x) = f(x). Using the product rule, h'(x)g(x) + h(x)g'(x) = f'(x). 501"\" for h'(x). we get MI) = W 3U) / . _l :0) max) gm =f'