f(x) = -(0.5) * x^(3.0) + 2.0 * x^(2.0) - x + 1.0
A = Point(xAxis)
B = Point(xAxis)
n = 27 (slider from 1 to 50, step 0.1)
SumaSuperior = UpperSum(f, x(A), x(B), n)
SumaInferior = LowerSum(f, x(A), x(B), n)
Diferencia: SumaSuperior - SumaInferior
texto1: "Suma Superior = " + SumaSuperior
texto2: "Suma Inferior = " + SumaInferior
texto3: "Diferencia = " + Diferencia