Answer
$\dfrac {\left( \ln x\right) ^{2}}{2}+c$
Work Step by Step
$v=\ln x\Rightarrow dv=\dfrac {1}{x}dx$
$$\Rightarrow \int \dfrac {\ln x}{x}dx=\int \ln x\times \dfrac {1}{x}dx=\int vdv=\dfrac {v^{2}}{2}+c=\dfrac {\left( \ln x\right) ^{2}}{2}+c$$
