# Lower and Upper Sum of a Function

Here you can see a function with its lower sum and upper sum on the interval [A,B]

1. Drag the endpoints A and B of the interval with the mouse .What characteristics of the rectangles of the rectangles of the (a) lower sum, (b)upper sum do ou see ？ 2.Now ,change the number of rectangles n by moving the slider with the mouse .How does this affect the diffference between lower and uppersum ？