Hey, I've got a set of questions concerning the Riemann Integral. It's especially difficult since I was absent for all of the classes concerning the topic. Any help would be greatly appreciated:

Consider f(x) = 2x + 1 over the interval [1,3]. Let P be the partition consisting of the points {1, 3/2, 2, 3}.

a. Compute L(f,P); U(f,P); and U(f,P) - L(f,P)

b. What happens to the value of U(f,P) - L(f,P) when we add the point 5/2 to the partition?

c. Find a partition P' of [1,3] for which U(f,P') - L(f,P') < 2.