a. Find the critical points of the following function on the given interval. b. Use a graphing utility to determine whether the critical points correspond to local maxima, local minima, or neither. c. Find the absolute maximum and minimum values on the given interval. f(0) = 2 sin 0 + 4 cos 0; [- 27,2n] a. Identify all the critical points. Select the correct choice below and fill in any answer boxes within your choice. O A. 0 = (Round to three decimal places as needed. Use a comma to separate answers as needed.) O B. There are no critical points.