Funktionsterm:

rechts = 2 (slider from -5 to 5)
links = -2 (slider from -5 to 5, step 0.1)
n = 26 (slider from 1 to 100, step 1)
f(x) = (-x^(2)) + 4
a = 11.26627192684094
b = 10.035503261885186
Text2: "Untersumme: " + b + ""
Text1: "Obersumme: " + a + ""
c = 10.666666666666666
Text3: "Tatsächliche Fläche: " + c + ""
Eingabefeld1 = Textfield(f)