Answer the questions for the function f(x) = - 3x3 + 3x- -x-3 a. Find formulas for f'(x) and f''(x). f'(x) = -9x+6x-1 f''(x)= -18x+6 Enter f(x), f'(x), and f''(x) into your grapher to examine the table. b. Set the first derivative f'(x) = 0 to find any critical values. Tip: You may wish to graph f'(x) by itself to explore if it any zeros. It can be helpful to know that the formula of f'(x) factors. Select the correct choice below and, if necess in the answer boxes within your choice. O A. The function f has a critical number at x= exact answer.) ; at this critical number, the second derivative f'(x) = (Typ OB. There are no critical numbers.