15. a. Find the open intervals on which the function is increasing and those on which it is decreasing. b. Identify the function's local extreme values, if any, saying where they occur. 1/3 f(x) x (x2-25) a. On what open intervals, if any, is the function increasing? Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. The function is increasing on the open interval(s) (Simplify your answer. Type your answer in interval notation. Type an exact answer, using radicals as needed. Use a comma to separate answers as needed.) O B. The function is never increasing. On what open intervals, if any, is the function decreasing? Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. The function is decreasing on the open interval(s) (Simplify your answer. Type your answer in interval notation. Type an exact answer, using radicals as needed. Use a comma to separate answers as needed.) B. The function is never decreasing. b. Find each local maximum, if any. Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. (Type exact answers, using radicals as needed.) O A. The function has a local maximum value at three values of x. In increasing order of x-value, the maximum values are f , and = = C and f B. The function has a local maximum value at two values of x. In increasing order of x-value, the maximum values are f O C. The function has a local maximum value at one value of x. The maximum value is f O D. There are no local maxima. Find each local minimum, if any. Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. (Type exact answers, using radicals as needed.) O A. The function has a local minimum value at one value of x. The minimum value is f( B. The function has a local minimum value at three values of x. In increasing order of x-value, the minimum values are and O C. The function has a local minimum value at two values of x. In increasing order of x-value, the minimum values are f and f = D. There are no local minima.