Suppose f is differentiable on ( - co, co) and assume it has a local extreme value at the point x= 10 where f(10) =0. Let g(x) = xf(x) + 4 and let h(x) = xf(x) + x +4 for all values of x. a. Evaluate g(10), h(10), g'(10), and h'(10). b. Does either g or h have a local extreme value at x = 10? Explain