3 (a) (3 points) Approximate the integral / 2x(x2 + 1) dusing a uniform partition with 4 rectangles, and left endpoints. 1 10 (b) (1 point) Approximate the integral / u dwsing the partition 2, 3.25, 5, 7.25, mind left endpoints. 1 How does your answer compare to part (a)? Note: the partition in part (b) is not uniform, so you will need to calculate each Aui. Notice that ui = x]? + for each i = 0, 1, 2, 3,4