Answer
$$\left[ \begin {array}{cccccc} 0&1\\
1&0\end {array} \right].$$
Work Step by Step
Since $ad-bc=(0)(0)-(1)(1)=-1\neq 0$, then the matrix has inverse given by
$$ - \left[ \begin {array}{cccccc} 0&-1\\
-1&0\end {array} \right]=\left[ \begin {array}{cccccc} 0&1\\
1&0\end {array} \right].$$
