f = Function(1.0 / x, 0.2, 100.0)
t = 4.6 (slider from 1 to 15, step 0.1)
a = Integral(f, 1.0, t)
b: log(t)
texto1 = Text("Área - log(t) = " + (a - b))
e = 2.718281828459045
A: (e, 0.0)
g = Function(log(x) - 1.0, 1.0, 20.0)