Etimate the area bounded by fx in x and the x-axis for 1

Question

Question: Estimate the area bounded by f(x) = In x and the x-axis for 1 ≤ x ≤ 4 using n = 100 rectangles and

(a) the left endpoint in each subinterval,

(b) the right endpoint in each subinterval and

(c) the midpoint of each subinterval.

Recall that the area of a trapezoid with bases b1 and b2 and height h is ½h(b1 + b2) see Figure.