Unless specified, all approximating rectangles are assumed to have the same width. Evaluate the upper and lower sums for f(x) = 1 + cos cos($) -ISXS*, with n = 3, 4, and 6. Illustrate each case with a sketch similar to the figure shown below. (Round your answers to two decimal places.) n = 3: upper sum ll lower sum n = 4: upper sum II lower sum n = 6: upper sum IO lower sum