Question 4. Score: 1/1 x² - 32x² Let f(x) = = 5 (a) Use the definition of a derivative or the derivative rules to find 3 f'(x) = 4x 5 64x 5 (b) Use the definition of a derivative or the derivative rules to find f" (x) = = 12x 5 64 5 (c) On what interval is f increasing (include the endpoints in the interval)? interval of increasing = [-4,0] U [4,∞) (d) On what interval is f decreasing (include the endpoints in the interval)? interval of decreasing = (-00,-4] U [0,4] (e) On what interval is f concave downward (include the endpoints in the interval)? interval of concave downward = -4√3 4√3 3 3 (f) On what interval is f concave upward (include the endpoints in the interval)? interval of concave upward = -00, -4√3 3 4√3 ,00 3