Compare upper and lower Riemann sums and their definite integral limits.

Either use the default function or enter a function of your choice.[br]Alternatively, drag the existing curve to a new position on the x-y plane.[br]Shift and click-scroll to zoom in and out. [br]Shift and click-drag to pan left/right/up/down. [br]Shift and click-drag on axis to rescale axis.[br]Drag points A and B along x-axis to adjust interval.[br]Check boxes for calculation methods to use. [br]Observe the effect of increasing the number n of sub-intervals