1. Interpreting Rate of Change and Slope
Section 5.3
Interpreting Rate of Change and Slope

2. Objective By following instructions students will be able to:
Relate rate of change and slope in linear relationships.

3. Explore
The rate of change over a part of the domain of the function is a ratio that
compares the change in y to the change in x in that part of the domain.
The table shows the year and the cost of sending 1-ounce letter in cents.

4. The slope of a line is the ratio of rise to run for any two points on the line.

5. Explain 1A
Determine the slope of each line.

6. Explain 1B
Determine the slope of each line.

7. Reflect #1
Find the rise of a horizontal line. What is the slope of a horizontal line?
Find the rise of a vertical line. What is the slope of a vertical line?
Your-Turn #1
Find the slope of each line.
a) b)

9. Explain 2A Find the slope of each line passing through the given
points using the slope formula. Describe the slope as
positive, negative, zero, or undefined.

10. Explain 2B

11. Your-Turn #2
Find the slope of each line passing through the given points using the slope formula.
Describe the slope as positive, negative, zero, or undefined.

12. Explain 3A Find and interpret the slope for each real-world situation.
The graph shows the relationship between a person’s age
and his or her estimated maximum heart rate.

13. Explain 3B The height of a plant y in centimeters after x days is a
linear relationship. The points (30, 15) and (40, 25) are
on the line.

14. Your-Turn #3 The graph shows the relationship between the
temperature expressed in °F and the temperature
expressed in °C.

15. Revisit Objective Did we…
Relate rate of change and slope in linear relationships?

16. Homework
HW:
Page 186 #s 1-18, 22, 23