a = 3 (slider from -5 to 5, step 0.05)
b = -11 (slider from -12 to 5, step 0.05)
c = 1 (slider from -5 to 5, step 0.05)
d = 20 (slider from -5 to 30, step 0.05)
f(x) = (a * x^(3)) + (b * x^(2)) + (c * x) + d
A = Integral(f, 0, 3)
h = 8.75 (slider from 0 to 10, step 0.01)
g: y = h
Aire = Integral(((-(x(g) / y(g))) * x) - z(g) / y(g), 0, 3)
Cf(x) = If[0 ≤ x ≤ 3, f(x)]
e: y = h