$m=\sqrt{x^{2}-n^{2}}-x$
$m=-\left(\sqrt{x^{2}-n^{2}}+x\right)\text{, }x\neq n\text{ and }|x|>|n|$

$n=\sqrt{-m\left(2x+m\right)}$
$n=-\sqrt{-m\left(2x+m\right)}\text{, }x\neq -m\text{ and }\left(m\geq 0\text{ or }x\geq -\frac{m}{2}\right)\text{ and }\left(m\leq 0\text{ or }x\leq -\frac{m}{2}\right)$