1. Copyright 2006 BrainyBetty.com ALL RIGHTS RESERVED. October 19, 2011 By the end of today: –I will be able to find slope from a graph. Warm-up: Graph y = -2x + 4 in your calculator. Determine the x-intercept and the y- intercept.

2. Homework Questions x Copyright 2006 BrainyBetty.com ALL RIGHTS RESERVED.

3. What is slope? If you drove 90 miles in two hours, what was your average speed? This is a rate of change! “Slope” is also called “rate of change”. It is helpful because it allows us to see how much something changes.

4. What is slope? Think about ski slopes. What does the word “slope” mean? Many things have a slope. Roads have a slope called grade.

5. Cliff the mountain climber climbs UP a mountain! + slope

6. Cliff the mountain climber falls DOWN a hill! - slope

7. Cliff takes it easy on a HORIZONTAL surface! ZERO slope “ Y ” would a mountain climber walk HORIZONTALLY ?

8. Cliff challenges himself on a VERTICAL surface! UNDEFINED slope After jumping VERTICALLY several times, he was “ X ” hausted

9. What’s the slope of Lance Berkman’s Bat? (Positive or Negative)

10. What’s the slope of Kobe Bryant’s arm? (Positive or Negative)

11. What’s the slope of the trees? (Positive or Negative)

12. Finding The Slope of 2 Points Copyright 2006 BrainyBetty.com ALL RIGHTS RESERVED. 1. Find the slope of the line below.  If you are given a line, find two “perfect” points on the line.  Count rise over run. counting rise over run y x

13. Finding The Slope of 2 Points Copyright 2006 BrainyBetty.com ALL RIGHTS RESERVED. 2. Find the slope of the line below.  If you are given a line, find two “perfect” points on the line.  Count rise over run. counting rise over run y x

14. Finding The Slope of 2 Points Copyright 2006 BrainyBetty.com ALL RIGHTS RESERVED. 3. Find the slope of the line below.  Remember? Slope of a horizontal line is 0. Think about if this were a ski slope. counting rise over run y x

15. Finding The Slope of 2 Points Copyright 2006 BrainyBetty.com ALL RIGHTS RESERVED. 4. Find the slope of the line below.  Remember? Slope of a vertical line is undefined. counting rise over run y x

16. Finding The Slope of 2 Points Copyright 2006 BrainyBetty.com ALL RIGHTS RESERVED. 5. The points (2, -3) and (0, -9) lie on a line. Graph the points. What is the slope? counting rise over run  Look at the line. Is it increasing or decreasing?  So should our slope be positive or negative?  Count rise over run.

17. Finding The Slope of 2 Points Copyright 2006 BrainyBetty.com ALL RIGHTS RESERVED. 6. The points (-6, 2) and (2, -8) lie on a line. Graph the points. What is the slope? counting rise over run

18. Try This A generator company installs generators over a number of days. The company is trying to use this graph to help them figure out when do they need to re-order generators to have a full stock. What is the slope of this line? What does the slope mean? What is the y intercept? In how many days will they have zero generators left? Copyright 2006 BrainyBetty.com ALL RIGHTS RESERVED.

19. Homework Worksheet Copyright 2006 BrainyBetty.com ALL RIGHTS RESERVED.