Use the graph of f' and f" to find the critical points and inflection points of f, the intervals on which f is increasing and decreasing, and the intervals of concavity. Then, graph Ay f assuming f(0) = 0. Find the critical points. The critical points are x = 2,6 . (Use a comma to separate answers as needed.) Find the inflection points. The inflection points occur at x = . (Use a comma to separate answers as needed.)