\(\int x \cdot(1+\ln x) d x \)
u´=x u=\( \frac{x^2}{2} \)
v=1+ln(x) v´=\( \frac{1}{x} \)
\(\int x \cdot(1+\ln x) d x \)=\( \frac{x^2}{2} \)*(1+ln(x))-\( \int\limits_{}^{} \)\( \frac{x^2}{2} \)*\( \frac{1}{x} \)*dx=
=\( \frac{x^2}{2} \)*(1+ln(x)) - \( \int\limits_{}^{} \)\( \frac{x}{2} \)*dx=
=\( \frac{x^2}{2} \)*(1+ln(x)) - \( \frac{x^2}{4} \) +C=
= \( \frac{x^2}{2} \)+\( \frac{x^2}{2} \)*lnx - \( \frac{x^2}{4} \) +C
= \( \frac{x^2}{4} \)+\( \frac{x^2}{2} \)*lnx +C