For any \(2\times2\) matrix \(\mathbf{A} = \begin{pmatrix} a & b \\ c & d \end{pmatrix}\), where \(a\), \(b\), \(c\) and \(d\) are real numbers, the determinant of \(\mathbf{A}\) is denoted by
\(|\mathbf{A}| = ad - bc.\)
If \(|\mathbf{A}| \neq 0\), the inverse matrix of \(\mathbf{A}\) denoted by
\(\mathbf{A}^{-1} = \frac{1}{|\mathbf{A}|} \begin{pmatrix} d & -b \\ -c & a \end{pmatrix} = \frac{1}{ad - bc} \begin{pmatrix} d & -b \\ -c & a \end{pmatrix},\)
such that \(\mathbf{AA}^{-1} = \mathbf{A}^{-1}\mathbf{A} = \mathbf{I}\), where \(\mathbf{I}\) is the identity matrix.
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