MTH 1222 Name: Thomas lance Written Problems 11.3 Directions for 1-3: Use Riemann sums to find an approximation of the area of the region R under the graph of the function f on the interval [a, b]. In each case, use n subintervals and choose the representative points as indicated. 1. f (x) = 4-x2; [-1, 2]; n=6; left endpoints 2. f ( x ) = - ; [1, 3] ; n = 4 ; right endpoints