1. Warm-Up

2. Finding The Slope of a Line
Unit 6 Day 1
Finding The Slope of a Line

3. Slopes are commonly associated with mountains.

4. The slope we are studying is associated with the graph of a line.

5. Definitions of Slope The tilt or inclination of a line
The ratio of vertical change to horizontal change.
The change in y over the change in x
Allow students time to copy
May need to review that a ratio is a comparison of numbers

6. Tilt or Inclination Discuss positive and negative slope.
Discuss when slope equals 0 and is undefined.

7. Types of Slope: Zero Positive Negative No Slope Or Undefined
Discuss positive and negative slope.
Discuss when slope equals 0 and is undefined.
Negative
No Slope
Or Undefined

8. Vertical Change Horizontal Change
SLOPE
Vertical Change Horizontal Change
This ratio is also known as
Rise
Run

9. How many points do you need to draw a line?
One
Two
Three
Quiz students

10. Ex 1: Graph (3,2) and (-1,-1)
Remember to click to make each part appear

11. Draw a line through the points.
Line will appear automatically

12. Ex 2: Now that we have our line lets find its slope.
Remember we are finding the following ratio:
Vertical or Rise
Horizontal Run

13. Vertical Change or the Rise3
Discuss vertical change

14. Horizontal Change or the Run4 3
Discuss horizontal change

15. Vertical Rise Horizontal Run3 4
May need to remind students that a ratio is a comparison of two numbers

16. Ex 3: Find the slope of the following line.

17. The slope is… 1 2

18. Ex 4: Find the slope of the line.

19. The slope is…. -3
Discuss why the slope is negative and that –3/1 reduces to –3.

20. Ex 5: Find the slope of these lines.
Have students practice.

21. The slope is…
Black line 3
Red Line 1
Blue Line -1/2

22. Ex 6: Find the slope of these lines

23. The slope is…
Orange line 0
Green Line Undefined

24. Let’s draw a line using slope.
What else do you think you need besides the slope in order to draw a line?
A point!

25. 7. If you know the slope and one point on the line you can draw the line. Example: slope is 1/3 and the point (-2,-1)

26. Now you draw a line. 8. Given: slope is 2/3 and the point is (1,0)

27. The graphs are…

28. Slope Formula
We can also find the slope of a line if we are given two points. We use the Slope Formula:

29. Ex 1:
Find the slope of a line given the points (3,-4) and (-7,1).

30. Find the slope of the line that passes between the points: Ex 2:(-2,6) and (-3,2) Ex 3:(4,1) and (4,-8) Ex 4:(0,-5) and (-11,-5)