4. Differentiate the following. Simplify your derivatives as much as possible. [10] a) f(x) = (3x2 - 4) b) y = ( vx+ 2)x-2) c) g(x) = (2x-1)4 u + 4 Vx+x and u = find ( x + 5 ) ? d) if y= - u - 4 2 when x = 4