f(x) = x^(3.0) - x^(2.0) - x + 2.0
A = Point(xAxis)
B = Point(xAxis)
n = 4 (slider from 1 to 500, step 1)
O = UpperSum(f, x(A), x(B), n)
U = LowerSum(f, x(A), x(B), n)
Text1: "Obersumme= " + O
Text2: "Untersumme = " + U
I = Integral(f, x(A), x(B))
Text3: "Integral = " + I