Use the graph off to find the largest open interval on which is increasing, and the largest open interval on which is decreasing. (Enter your answers using interval notation.) 2 -2 2 N. N 4 (a) Find the largest open interval(s) on which f is increasing. (If two open intervals are equally large enter your answer as a comma-separated list of intervals.) (b) Find the largest open interval(s) on which f is decreasing. (If two open intervals are equally large enter your answer as a comma-separated list of intervals.)