Answer :

[tex]$\left(\ln(|x|)\right)'=\frac{1}x$[/tex] hence [tex]\int\frac{1}xdx=\ln |x|[/tex]
[tex]F(x) = \int\limits \frac{1}{x} dx =\int\limits x^-^1 dx \\ f(x) = \int\limits x^-^1dx = \frac{1}{0} X^0[/tex]

[tex]= f(x) = \int\limits X^-^1dx = In|x|[/tex]