Condition for a Matrix to Be Invertible
A square matrix is invertible (also called non-singular) if there exists another matrix, called its inverse, such that A^-1 A=A A^-1=I, where I is the identity matrix of the same order.

The key condition for a matrix to be invertible is that its determinant must not be zero, i.e., {det}(A) not equal to 0.

If {det}(A)=0, the matrix is called singular and does not have an inverse.
Invertible matrices are essential in solving systems of linear equations, finding matrix equations, and various applications in linear algebra.