3. Write an example of matrices B, A such that A is k x n and B is n x k for some positive integers k, n, BA is equal to the identity n x n matrix In, and AB is not equal to the identity k x k matrix...

Extracted text: 3. Write an example of matrices B, A such that A is k x n and B is n x k for some positive integers k, n, BA is equal to the identity n x n matrix In, and AB is not equal to the identity k x k matrix I. 4. Consider the matrix [1 2 0 2] 0 1 0 1 2 1 1 2 0 10 2 A Determine whether A is invertible. If A is invertible, compute its inverse.