The graph of the derivative f' of a continuous function is shown. (Assume / continues to m.) y 4 y=f'(x) -2 -21 x 6 18 (a) On what interval(s) is increasing? (Enter your answer in interval notation.) On what interval(s) is f decreasing? (Enter your answer in interval notation.) D (b) At what value(s) of x does have a local maximum? (Enter your answers as a comma-separated list.) x = At what value(s) of x does / have a local minimum? (Enter your answers as a comma-separated list.) X = (c) On what interval(s) is concave upward? (Enter your answer in interval notation.) On what interval(s) is / concave downward? (Enter your answer in interval notation.) (4) State the x-coordinate(s) of the point(s) of inflection. (Enter your answers as a comma-separated list.) x =