$$y=\frac{\tan\ x}{x}\cdot e^{x}\log\ x$$
$y=-\frac{\log(x)\left(ie^{\left(1+i\right)x}-ie^{\left(1-i\right)x}\right)}{2x\cos(x)}$
$\nexists n_{1}\in \mathrm{Z}\text{ : }x=\pi n_{1}+\frac{\pi }{2}\text{ and }x\neq 0$
$y=\frac{\log(x)\tan(x)e^{x}}{x}$
$\nexists n_{1}\in \mathrm{Z}\text{ : }x=\pi n_{1}+\frac{\pi }{2}\text{ and }x>0$
