Estimate the area under the curve using rectangles or trapezoids.

Choose the number of subintervals on [math][a, b][/math] by sliding the "[math]n[/math]" slider. Check the "Trapezoidal Sum" box for a trapezoidal approximation; otherwise clear it for a rectangular sum. For a rectangular sum, choose the position of the [math]y[/math]-value within the interval using the "[math]p[/math]" slider.