1. Given y = 4(u^3) - u and u = sqrt x, a) Determine dy/dx at x = 9 using the Leibniz form of the chain rule. b) Determinedy/dx at x = 9 by first rewriting the question using only variables x and y. 2. A parabola which represents y' opens down with x-intercepts at x = -4 and x = 0. Sketch this parabola, and use it to sketch y and y''.