$\left\{\begin{matrix}a=\frac{b^{2}}{x}\text{, }&b\geq 0\text{ and }x\neq 0\\a\in \mathrm{R}\text{, }&b=0\text{ and }x=0\end{matrix}\right.$

$\left\{\begin{matrix}a=\frac{b^{2}}{x}\text{, }&x\neq 0\text{ and }\left(b=0\text{ or }arg(b)<\pi \right)\\a\in \mathrm{C}\text{, }&b=0\text{ and }x=0\end{matrix}\right.$

$b=\sqrt{ax}$

$b=\sqrt{ax}$
$\left(x\geq 0\text{ and }a\geq 0\right)\text{ or }\left(a\leq 0\text{ and }x\leq 0\right)$