<Li> det A = (det A). </Li> <P> A matrix that is its own inverse, i.e. such that A = A and A = I, is called an involutory matrix . </P> <P> The adjugate of a matrix A (\ displaystyle A) can be used to find the inverse of A (\ displaystyle A) as follows: </P> <P> If A (\ displaystyle A) is an n × n (\ displaystyle n \ times n) invertible matrix, then </P>

When does the inverse of a matrix exist