Integration Application: Area of Rectangles and Area under the Curve

This is a common type of question which involves using rectangles of equal width to estimate the area under the curve. There are two ways to draw the rectangles. One way will give you an underestimate of the exact area while the other way will give you an overestimate. In this question, both ways are explored and we zoom in on the approach of how to prove the total area of n number of rectangles is expressed in summation form.