4. The graph of a function f(x) is given below. - 4 - 3 Circle the correct option below for the interval (-co, -3) a ) f' (x) >0 and f" ( x) >0 b ) f' ( x ) >0 and f" (x)0 d ) f' ( x)0 c) on [a, b] f'(x)>0 and f"(x/0 d) on [a, b] f'(x)>0 and f" ( x) >0 46. f(x) =x4-8x2 a) Determine the critical points of f(x) and create a first derivative sign chart. b) What are the intervals where the function is increasing and decreasing. c) Classify the critical points as maxima, minima or neither. 5