$\theta =2\pi n_{1}+\arctan(\frac{3}{4})\text{, }n_{1}\in \mathrm{Z}$
$\theta =2\pi n_{2}+\pi -\arctan(\frac{3}{4})\text{, }n_{2}\in \mathrm{Z}$

$\theta =2\pi n_{1}+\arcsin(\frac{3}{5})\text{, }n_{1}\in \mathrm{Z}$
$\theta =2\pi n_{2}+\pi -\arcsin(\frac{3}{5})\text{, }n_{2}\in \mathrm{Z}$