(a) Estimate the area under the graph of the function f (a) = - 1 from x = 0 to a = 1 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) = ! from x = 0 to * = 1 using a Riemann sum with n = 10 subintervals and left endpoints. Round your answer to four decimal places. area Number