2 10/05

1. New: 6.2.8. Old: 5.2.8. Neatly and clearly graph the plane in 3D space.

2. New: 7.7.13. Old: 6.7.13. Follow the same, completely written out, procedure as used in class for 7.37.

3. New: 7.7.13. Old: 6.7.13. Follow the same, augmented matrix procedure as used in class for 7.37.

4. New: 7.2.6. Old: 6.2.6. (``by 4'', not ``by row 4'') Find $\Omega$ as the product of the elementary matrices of the row operations.

5. New: 7.3.6. Old: 6.3,6. Find $\Omega$ as the product of the elementary matrices of the row operations. Do it two ways: (a) by first interchanging the two rows; (b) without row exchanges. You should find that $\Omega_a$ and $\Omega_b$ are not the same. Are the reduced matrices $A_{Ra}$ and $A_{Rb}$ the same, as theorem 7.10 (6.10) claims? Show that if $A$ would have been a nonsingular square matrix, $\Omega_a$ and $\Omega_b$ would have been the same.