Adjoint of a 2x2 matrix for JEE

Formula

\[\operatorname{adj}\begin{bmatrix}a&b\\c&d\end{bmatrix}=\begin{bmatrix}d&-b\\-c&a\end{bmatrix}\]

Variables: \(a,b,c,d\): entries of the matrix.

Conditions: For a \(2\times 2\) matrix.

Quick inverse of order 2 matrices.