$\left\{\begin{matrix}c=\frac{7\cot(\theta )}{o}\text{, }&\exists n_{1}\in \mathrm{Z}\text{ : }\left(\theta >\pi n_{1}\text{ and }\theta <\pi n_{1}+\pi \right)\text{ and }o\neq 0\\c\in \mathrm{R}\text{, }&\exists n_{2}\in \mathrm{Z}\text{ : }\theta =\pi n_{2}+\frac{\pi }{2}\text{ and }o=0\end{matrix}\right.$

$\left\{\begin{matrix}o=\frac{7\cot(\theta )}{c}\text{, }&c\neq 0\text{ and }\nexists n_{1}\in \mathrm{Z}\text{ : }\theta =\pi n_{1}\text{ and }\exists n_{1}\in \mathrm{Z}\text{ : }\left(\theta >\pi n_{1}\text{ and }\theta <\pi n_{1}+\pi \right)\\o\in \mathrm{R}\text{, }&\exists n_{2}\in \mathrm{Z}\text{ : }\theta =\pi n_{2}+\frac{\pi }{2}\text{ and }c=0\end{matrix}\right.$