1. Slopes of Lines
Section 3-3

2. Definition of Slope
The slope m of a line containing 2 points with coordinate (x1, y1) and (x2, y2) is given by the formula: )

3. Postulate 3-2 and 3-3
2 nonvertical lines have the same slope iff they are parallel.
2 nonvertical lines are perpendicular iff the product of their slopes is –1.

4. undefined slope
zero slope
positive slope
negative slope

5. Joke Time
What do you call a hippo in a phone booth?
stuck

6. What would America be called if we all drove pink cars?
A pink carnation