Question:
Evaluate the following integrals:
$\int \frac{\mathrm{e}^{\mathrm{x}}}{\mathrm{x}}\left\{\mathrm{x}(\log \mathrm{x})^{2}+2 \log \mathrm{x}\right\} \mathrm{dx}$
Solution:
Let $I=\int \frac{e^{x}}{x}\left\{x(\log x)^{2}+2 \log x\right\} d x$
$=\int e^{x}(\log x)^{2} d x+2 \int \frac{e^{x}}{x} \log x d x$
Using integration by parts,
$=e^{x}(\log x)^{2}-\int e^{x} \frac{d}{d x}(\log x)^{2}+2 \int \frac{e^{x}}{x} \log x d x$
$=e^{x}(\log x)^{2}-2 \int \frac{e^{x}}{x} \log x d x+2 \int \frac{e^{x}}{x} \log x d x$
$=e^{x}(\log x)^{2}+c$