1. 7.4 Constant Rate of Change
Unit 7, Lesson 4
Pg. 487

2. Happy Birthday
Period 3
Daniel Rios Garcia
Elijah Peoples

3. Objective and Vocabulary
Relationships, Straight lines, and Linear
Constant Rate of Change in a relationship
Vocabulary
Rate of Change
Linear Relationships
Proportional Relationships
Slope
Rise over Run

4. Rate of Change
A ratio that compares the amount of change in the Dependent Variable (y’s - rise) to the amount of change in the independent Variable (x’s - run)
Table format or between 2 points
Remember direction on the axis (change between 2 points)
Up and down is positive and negative on the y-axis
Right and left is positive and negative on the x-axis

5. Example #1

6. Example #2 Finding rates of change from a graph (using 2 points)
A to B
B to C
C to D
D to E
E to F

7. Pick any two “2” points…. You must label and graph them…
Draw a line between the two points
We will now find the rate of change between the two points.
Label 1, pt. 1 and the other pt. 2, just like you did with the distance formula
Now we will use the slope formula and find the slope of the line.
Remember, on a straight line, the slope will remain constant.

8. Example of a Straight Line

9. Greater Slope? The steeper a line is, the greater the rate of change
The greater value (absolute value), the greater the rate of change

10. Linear Relationships Relationships that have straight-line graphs are
What is the rate of change?
Number of Songs, y 2 4 6 8
Time (minutes), x 1 3

11. Proportional Relationships
Two quantities “a” and “b” have a proportional linear relationship if they have a constant ratio and a constant rate of change

12. Example #2

13. Homework
Honors
Pg. 491, 1 – 13 all
Regular
Pg. 491, 1 – 10, 13