7.1 Integration By Parts/28

$\int _{1}^{2}{\frac {(\ln {x})^{2}}{x^{3}}}$

$u=\ln {x}\qquad dv={\frac {1}{x^{3}}}$

$du={\frac {1}{x}}\qquad v=-{\frac {1}{2x^{2}}}$

${\begin{aligned}\int _{1}^{2}{\frac {\ln {x}^{2}}{x^{3}}}&=-{\frac {\ln ^{2}{(x)}}{2x^{2}}}-\int -{\frac {\ln {(x)}}{x^{3}}}&&=-{\frac {\ln ^{2}{(x)}}{2x^{2}}}+\int {\frac {\ln {(x)}}{x^{3}}}\\[2ex]&&=-{\frac {\ln {(x)}}{2x^{2}}}-{\frac {1}{2}}\int {\frac {1}{x^{3}}}\\[2ex]&=-{\frac {\ln {(x)}}{2x^{2}}}-{\frac {1}{4x^{2}}}\end{aligned}}$