13. Consider the functions f(x) = 2 cos x and g(x) = 0.5x2. Let d(x) be the vertical distance between these two functions. (a) Find the rate of change of d(x) at x = 1. (b) Find the rate of change of d(x) at x = 2. 14. The graph of g', the derivative of the function g, is shown above for - 2 S x S 4. (a) On what interval (s) is g decreasing? (b) On what interval(s) is g decreasing and concave up? (c) Identify any value(s) of x where g has points of inflection. graph of g' Explain your reasoning. 24 (d) Identify any value(s) of x where g has a relative maximum or relative minimum on (-2, 4). Explain your reasoning