The graph of f is shown in the figure. 4 -4 (a) For which values of x is f'(x) zero? (Enter your answers as a comma-separated list.) For which values of x is f'(x) positive? (Enter your answer using interval notation.) For which values of x is f'(x) negative? (Enter your answer using interval notation.) What do these values mean? f is ---Select--- O when f'> 0 and f is ---Select--- O when f' < 0. (b) For which values of x is f"(x) zero? (Enter your answers as a comma-separated list.) For which values of x is f"(x) positive? (Enter your answer using interval notation.) For which values of x is f"(x) negative? (Enter your answer using interval notation.) What do these values mean? f is ---Select--- when f"> 0 and f is ---Select--- when f" < 0. (c) On what open interval is f' an increasing function? (d) For which value of x is f'(x) minimum? For this value of x, how does the rate of change of f compare with the rates of change of f for other values of x? Explain. The rate of change of f at this value of x is ---Select--- * the rate of change of f for all other values of x.