Demonstration of using Rectangles to calculate Lower Sums & Upper Sums

The graph below allows you to control the number of rectangles used to calculate the lower and upper sums for the given curve. The upper sums are in the lighter blue and the lower sums are in the darker blue. Notice what happens to each of hese areas as the number of rectangles is increased or decreased.

                                                                                                                                                           (c) andrew beiderman 2007