Section 13.1 Worksheet:

Assigned problems: Exercises p. 821, #2, 3, 7, 10, 12, 13, 16, 22, 25, 30, 32, 36, 38 (due Wednesday, 10/29).

1. Follow the ``proof'' of the distance formula in three-dimensions on page 819. How does it work?

2. What is a Cartesian product?

3. How many constraints give rise to a plane in three-dimensions? How many constraints give rise to a line in three-dimensions?