f'(x) = (b) Check to see that your answer to part (a) is reasonable by comparing the graphs of f and f'. (A graphing calculator is recommended.) 100 y y 100 50 f -50 -4 -2 -100 y 100 50 -50 -100 x 2 4 50 x 4 4 -2 2 4 -2 4 -50 -100 y 100 50 -50 -100 2 4