9. Find all solutions in positive integers of the diophantine equation $x^{2}+3 y^{2}=z^{2}$.
9. $x=\frac{1}{2}\left(m^{2}-3 n^{2}\right), y=m n, z=\frac{1}{2}\left(m^{2}+3 n^{2}\right)$ where $m$ and $n$ are positive integers, $m>\sqrt{3} n$, and $m \equiv n(\bmod 2)$