Question

Which operation is performed immediately after selecting \(a_{ij}\) to find \(M_{ij}\)?

Options

• Calculate the determinant of the original matrix.

• Multiply every entry by \((-1)^{i+j}\).

• Delete the \(j\)-th row and \(i\)-th column of the matrix.

• Delete the \(i\)-th row and \(j\)-th column of the matrix.

Answer 1

The minor is based on the submatrix left after deleting row \(i\) and column \(j\). The deleted row and column are precisely those in which \(a_{ij}\) lies.