Find x, y, z if A = satisfies A¢ = A-1.
$\left[\begin{array}{ccc}0 & 2 y & z \\ x & y & -z \\ x & -y & z\end{array}\right]$
Matrix A is such that A¢ = A-1
AA¢ = I
$\left[\begin{array}{ccc}0 & 2 y & z \\ x & y & -z \\ x & -y & z\end{array}\right]\left[\begin{array}{ccc}0 & x & x \\ 2 y & y & -y \\ z & -z & z\end{array}\right]=\left[\begin{array}{ccc}1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1\end{array}\right]$
$\left[\begin{array}{ccc}4 y^{2}+z^{2} & 2 y^{2}-z^{2} & -2 y^{2}+z^{2} \\ 2 y^{2}-z^{2} & x^{2}+y^{2}+z^{2} & x^{2}-y^{2}-z^{2} \\ -2 y^{2}+z^{2} & x^{2}-y^{2}+z^{2} & x^{2}+y^{2}+z^{2}\end{array}\right]=\left[\begin{array}{lll}1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1\end{array}\right]$
$4 y^{2}+z^{2}=1$
$2 y^{2}-z^{2}=0$
$x^{2}+y^{2}+z^{2}=1$
$x^{2}-y^{2}-z^{2}=0$
$y^{2}=1 / 6, z^{2}=1 / 3, x^{2}=1 / 2$
So, the roots are:
$x=\pm \frac{1}{\sqrt{2}}$
$y=\pm \frac{1}{\sqrt{6}}$
And,
$z=\pm \frac{1}{\sqrt{3}}$