This interactive figure illustrates the approximation of the area under a curve using the [b]right endpoint rectangles, [/b][b]left endpoint rectangles[/b], and [b]midpoint rectangles[/b]. The approximation is calculated using [math]n[/math] equal-width rectangles. Observe how all three approximations get better as [math]n[/math] increases.

[i]Developed for use with Thomas' Calculus, published by Pearson.[/i]