1. Warm - Up
Identify the x – coordinate and y – coordinate of
each ordered pair.
(-3,4) (0,-7)
(5,0) (-9,-2)

2. Section 4.4 The Slope of a Line
 Definitions:
 Slope – of a non-vertical line is the number of
units the line rises or falls for each unit of
horizontal change from left to right.
 Rate of Change – slope is an important way of
visualizing a rate of change
2 1
2 1
rise changeiny y y
Slope
run changeinx x x
−
= = =
−

3. Classifications of line by slope

4. Example One
 Find the slope of the line passing through (-
2,2) and (3,4).

5. Example Two
 Find the slope of the line passing through (-
1,2) and (3,2).

6. Example Three
 Find the slope of the line passing through (0,0)
and (3,-3).

7. Example Four
 Find the slope of the line passing through (2,4)
and (2,1).

8. Example Five
 Find the value of y so that the line passing
through the points (-2,1) and (4,y) has a slope
of 2/3.

9. Example Six
 Find the value of y so that the line passing
through the points (3,y) and (5,8) has a slope
of 2.

10. Example Six
 Find the value of y so that the line passing
through the points (3,y) and (5,8) has a slope
of 2.