Can somebody plz try to solve the matrices sum in the attached figure??
After multiplying this, we get,
$\displaystyle \begin{pmatrix}
x^2+y^2 &0\\
0 & -x^2-y^2
\end{pmatrix}
=
\begin{pmatrix}
1 &0\\
0 & -1\\
\end{pmatrix}$
Then, we have,
$\displaystyle x^2+y^2=1$
and all possible pairs are,
$\displaystyle (x,y)=(1,0), (0,1), (-1,0),(0,-1)$