(a) Estimate the area under the graph of the function f (r) = from x = 0 to x = 3 using a Riemann sum with n = 10 subintervals and right endpoints. Round your answer to four decimal places. area = (b) Estimate the area under the graph of the function f (z) = Round your answerto four decimal places. area = from x 0 tox = 3 using a Riemann sum with n = 10 subintervals and left endpoints