Please help

1. a. Use the Left Hand Rule with 5 rectangles to approximate / (x2 -x)dx. Show your work. b. Use the Fundamental Theorem to compute the exact value of / (x2 - x) dx. Show your work. c. How close is the approximation to the exact value? _ Hint 2. Complete the following computation to cos (a) dx. V4 sin(a) + 2 Set u = 4 sin(x) + 2. Then du = ? dx. 7 /3 cos (ac) T. / 4 4 sin (2) + 2