(a) Estimate the area under the graph of the function f (a) = 1 2 +8 from x = 0 to x = 5 using a Riemann sum with n = 10 subintervals and right endpoints. Round your answer to four decimal places. area = Number (b) Estimate the area under the graph of the function f (a) = 1 from x = 0 to x = 5 using a Riemann sum with n = 10 subintervals and left endpoints. Round your answer to four decimal places. area = Number