Riemann sums are approximations of the area under a curve, so they will almost always be slightly more than the actual area (an overestimation) or slightly less than the actual area (an underestimation).

r2 Estimate the area under the graph of f(x) = 1 + and above the x-axis from x = 0 to x = 4 by using a left Riemann sum with four approximating rectangles. That is, use the function value at the left endpoints of the base of the to get the height. No credit for giving an exact answer using integration. ectangles (c) Is your answer and overestimate or an underestimate to the actual area?

Estimate the area under the graph of rx) 5 cos(x) from x = 0 to x = π/2. (Round the answer to four decimal places.) (a) Use four approximating rectangles and right endpoints. R4 = 4.954 Is your estimate an underestimate or an overestimate? underestimate overestimate (b) Use four approximating rectangles and left endpoints. L4 Is your estimate an underestimate or an overestimate? underestimate overestimate