Answer the following questions about the function whose derivative is given below. a. What are the critical points of f? b. On what open intervals is f increasing or decreasing? c. At what points, if any, does f assume local maximum and minimum values? f'(x) = (9 sin x 9) (2 cos x+3), 0x 2 a. What are the critical points of f? X= (Use a comma to separate answers as needed.) b. On what open intervals is f increasing or decreasing? (Use a comma to separate answers as needed.) A. The function f is decreasing on the open interval(s) B. The function f is increasing on the open interval(s) C. The function f is increasing on the open interval(s) and never increasing. and decreasing on the open interval(s) and never decreasing. c. At what points, if any, does f assume local maximum values? (Use a comma to separate answers as needed.) A. The function f has a local maximum at x = B. There is no local maxima. At what points, if any, does f assume local minimum values? (Use a comma to separate answers as needed.) A. The function f has a local minimum at x = B. There is no local minima.