Use the graph of f 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.) 6 4 2 6 K -2 (a) Find the largest open interval(s) on which fis 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 fis decreasing. (If two open intervals are equally large enter your answer as a comma-separated list of intervals.)Use the graph to estimate the open intervals on which the function is increasing or decreasing. Then find the open intervals analytically. (Enter your answers using interval notation.) increasing decreasing 15 10 -10 -8 -6 4 - 2 4 10 -10 -15 64 - 3rStep 1 Previously we found that f(x) = -6x + 12 and that the critical number is x = 2. The table below summarizes the testing of the two intervals determined by the critical number. Interval -00