please answer in comments, i cannot open files

Complete the following steps for the given function, interval, and value of n. a. Sketch the graph of the function on the given interval. b. Calculate Ax and the grid points Xo, X1, ..., Xn- c. Illustrate the left and right Riemann sums, and determine which Riemann sum underestimates and which sum overestimates the area under the curve. d. Calculate the left and right Riemann sums. f(x) = cos (x - 31/8) on [31/8,7x/8]; n=4 a. Sketch the graph of f(x) = cos (x - 3x/8) on the interval 8 ' 8 Choose the correct graph below. O A. O B. O c. OD. Ay Ay X TITT b. Ax= (Type an exact answer, using it as needed.) List the grid points. (Use a comma to separate answers as needed. Type exact answers, using it as needed.) c. Illustrate the left Riemann sum. Choose the correct graph below. O A. O B. O C. OD. Ay 1- Ay N N 0.5- 0.5- 7 /2