Use the graph of f to find the largest open interval on which f is increasing, and the largest open interval on which fis decreasing. (Enter your answers using interval notation.) 6 4 2 -2 2 6 X 2 (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.)