Question

A is invertible if it doesn't have a zero row or column

Answer 1

if AB = I, then BA = I, i.e., B is also invertible and an inverse of A. a square matrix with a row or column of zeros is singular it has no inverse. The row or columnof zeros causes the result of matrix multiplication to also have a row or column of zeros, it can't be I.

and also s quare matrix that is not invertible is called singular . A square matrix is singular if and only its determinant is 0. However, in some cases such a matrix may have a left inverse or right inverse


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