2. Finding The Slope of a Line

3. Slope! What is it? How do we use it? Is it ever used in the “ real world ” ?

4. Slopes are commonly associated with mountains.

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

8. 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

9. Tilt or Inclination

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

11. How many points do you need to draw a line? One Two Three

12. Slope Formula: Given (x1, y1) and (x2, y2)

13. Find Slope given: (3, 2) and (-1, -1)

14. Graph (3,2) and (-1,-1)

15. Draw a line through the points.

16. 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!

17. 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)

18. Now that we have our line lets find its slope. Remember we are finding the following ratio: Vertical orRise HorizontalRun

19. Vertical Change or the Rise 3

20. Horizontal Change or the Run 4 3

21. Vertical Rise Horizontal Run 3 4

22. IMPORTANT! When you use the formula for slope, the order of the subtraction is important. You must form the numerator and the denominator using the same order of subtraction.

23. Find the slope of the following line.

24. The slope is… 1 2

25. Find the slope of the line.

26. The slope is…. -3

27. Find the slope of these lines.

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

29. Find the slope of these lines

30. The slope is… Orange line0 Green LineUndefined

31. Now you draw a line. Given: slope is 2/3 and the point is (1,0) Given: slope is –3 and the point is (–2,4) Given: slope is 1 and the point is (2,3)

32. The graphs are…