1. Rate of Change and Slope Monday, November 1, 2010

2. Definition Rate of change allows you to see the relationship between two quantities that are changing.

3. Formula Rate of change =

4. Finding the Rate of Change Using a Table Cost of Renting a Computer Number of Days Rental Charge 1$60 2$75 3$90 4$105 5$120 Rate of change = The rate of change is $15 per day after the first day of rental.

5. Finding Rate of Change Using a Graph Rate of change = Use two points Divide Simplify

6. Slope Formula Slope = = where x 2 – x 1 0

7. Find Slope Using Two Points Slope = Find the slope of the line through A(-2, 1) and B (5, 7). the slope of Line AB is

8. Find the slope of the line through each pair of points. C (2, 5) and D (4, 7) – Slope is 1. P (-1, 4) and Q (3, -2) – Slope is

9. Horizontal and Vertical Lines Slope = Substitute two points The slope of a horizontal line is 0.

10. Slope = Substitute two points The slope of the vertical line is undefined.

11. Find the slope of the line. Slope = 0

12. Find the slope of the line. Slope = undefined

13. Find the slope of the line. Slope = undefined

14. Find the slope of the line. Slope = 0

15. Closure What are two ways to find the slope of a line? – You can count the units of rise and run between two points on graph. Or you can find the difference of the y-coordinates, and, in the same order, the difference of the x-coordinates. Then write the quotient of the difference of the y-coordinates divided by the difference of the x-coordinates.