2.  Definition: An Identity Matrix is a square matrix that, when multiplied by another matrix, equals the same matrix.  Form: In the Identity Matrix the entries on the diagonal are 1 and the other entries are 0.

3. WWhen using a 2x2 matrix the identity matrix is WWhen using a 3x3 matrix the identity matrix is

5. IIf, find I so that WWhat are the dimensions of N? SSo what is I?

6.  Definition: the matrix by which another matrix is multiplied that results in the identity matrix  Form:

7. A matrix will have an inverse if and only if

8. Find the inverse of M.

9. If, find