Question:
State whether the matrix $\left[\begin{array}{ll}2 & 3 \\ 6 & 4\end{array}\right]$ is singular or non-singular.
Solution:
Let $\Delta=\mid \begin{array}{ll}2 & 3\end{array}$
$6 \quad 4 \mid=\{(2 \times 4)-(6 \times 3)\}=8-18=-10$
A matrix is said to be singular if its determinant is equal to zero.
Since $\Delta=-10 \neq 0$, the given matrix is non $-$ singular.