The graph below is the derivative, f(x), of the continuous function f(x). -5 -5 -5 --6 -7 -8 -9 -10 7 9 10 27 For the function f(x): a) State the critical numbers. Explain how you know they are the critical numbers. b) State the intervals of increase and decrease. Justify your answers. c) Identify which critical numbers represent a local minimum and explain how you! know.