The checkmark in parentheses means that the 2nd Laplace Theorem is implicitly used in Proof 3, since you need it to prove the formula for the inverse of a matrix A in terms of its determinant and adjoint.
The checkmark in parentheses means that the 2nd Laplace Theorem isimplicitly used in Proof 3, since you need it to prove the formula for theinverse of a matrix A in terms of its determinant and adjoint.