f(x)=1/x

F(x)=ln(x)

f = Function(1 / x, 0, 10)
g(x) = log(x)
a = 3.527818249296733 (slider from 0 to 5, step 0.001)
A: (a, log(a))
Aire = Integral(1 / x, 1, a)
B: (a; 0)