A simple applet for approximating the area under a curve by rectangular sums.[br][br]We approximate the area under y=f(x) over the interval [a,b] with n rectangles.[br]The parameter p indicates where the approximation is made on each rectangle.[br]For left sums, p=0, and for right sums p=1.[br]You can stretch or shrink an axis by choosing the move tool (the 4 arrows) and moving a point of an axis in or out.