Find all 2 x 2 skew-symmetric matrices A Find all $2 \times 2$ skew-symmetric matrices $A$, if any, such that $A^2 + I_2 = 0$
Please help me! Thanks!!

Hint: Every $2\times 2$ skew-symmetric matrix has the form $\begin{pmatrix}0&t\\-t&0\end{pmatrix}$, so all you need to do is find those $t$ that have the desired property. Writing out the elements of $A^2+I$ explicitly would lead you a long way.
