1. SLOPE and RATE of CHANGE

2. Slope – a specific rate of change. It measures the change in the vertical axis over the change in the horizontal axis. - a ratio that describes steepness.

3. Positive vs. Negative A line with a positive slope goes upward from left to right A line with a negative slope goes downward from left to right

4. Count using the coordinate grid Calculating slope from a graph Use coordinates themselves

5. A (0, 12) and B (100, 212) Calculating slope from 2 given points (4,0) and (-1, 5)

6. The slope of a horizontal line is zero. Division by zero is undefined. The slope of a vertical line is undefined. Horizontal vs. Vertical Lines Some lines are neither upward or downward sloping. They can be calculated the same way.

7. A summary is also in the Book on page 312

8. Choose 2 points and find the slope Calculating slope from a table of values If the change between consecutive pairs of data are constant, the relationship is linear. X0100200 300 400 500 Y025 50 75 100 125 X0100200 300 400 500 Y025 50 75 100 125 Try the calculation again using two different points.

9. Slope is also sometimes referred to as rate of change. Independent Variable = x Dependent Variable = y Rate of Change - a comparison between two quantities that are changing. - Allows you to see the relationship between 2 quantities that are changing.

10. If you type 140 words in four minutes, what is your rate? Calculating Rate of Change If you buy 5 yards of fabric for $19.95, what is the rate? You travel 268.8 miles on 12 gallons of gas, what is your rate?

11. ¿Preguntas? est-ce que vous en avez?

12. Assignments Class Work Page 312#1 – 6 Page 313#7 – 9, 11 – 21 odd, 22 – 26 #27 – 35 odd, 36 – 41 Page 314#43, 48 – 60, 62 Early Finishers#66 – 71 Homework Page 315 #78 - 87