1. Rate of Change and y-intercept
Unit 2 Review
Rate of Change and y-intercept

2. Today, students will be identifying the rate of change and the y-intercept by using given information.
Each student will need a commutator board, a dry ease marker and a wipe.

3. A tire company notices that one of the tires they make that has a tread of 25 millimeters wear down of a millimeter every month.
What is the rate of change in the context of the problem?
5/8 millimeter of tread lost every month
-5/8 millimeter of tread every month

4. A tire company notices that one of the tires they make that has a tread of 25 millimeters wear down of a millimeter every month.
What does y-intercept represent in the context of the problem?
The tire loses 5 mm of tread every 8 months.
The tire starts with 8 mm of tread.
The tire starts with 25 mm of tread.
The tire loses 8 mm of tread every 5 months.

5. A doe is 12 feet from a stream
A doe is 12 feet from a stream. It walks towards the stream at a speed of 4 feet per second.
What is the rate of change?
-4 feet per second

6. A doe is 12 feet from a stream
A doe is 12 feet from a stream. It walks towards the stream at a speed of 4 feet per second.
Which graph shows the doe’s distance from the stream as a function of time?
A B C.

7. A collector’s coin was purchased in 2005
A collector’s coin was purchased in The equation below shows the value, f(x), of the coin x years after 2005.
Based on the equation, which statement is true.
The cost was $17.95 in 2005 and is decreasing by $2.35 per year.
The cost was $17.95 in 2005 and is increasing by $2.35 per year.
The cost was $2.35 in 2005 and is decreasing by $17.95 per year.
The cost was $2.35 in 2005 and is increasing by $17.95 per year.

8. Marie has a checking account at a bank
Marie has a checking account at a bank. The bank charges a monthly fee of $15.00 and then charges $0.25 for each check she writes.
Based on the equation, which statement is true.
The monthly fee is $15.00 and amount per check is $0.25.
The monthly fee is $0.25 and amount per check is $15.00.
The monthly fee is $1.00 and the amount per check is $0.25.
The monthly fee is $1.00 and the amount per check is $15.00.

9. How much money did Antonio start with in his savings account?
Antonio has a savings account and he make regular deposits into the account.
How much money did Antonio start with in his savings account?
$200
$150
$100
$50
months

10. How much money is Antonio saving every month?
Antonio has a savings account and he make regular deposits into the account.
How much money is Antonio saving every month?
$200 per month
$150 per month
$100 per month
$50 per month
months

11. Bamboo grows very fast. The equation below shows the height, f(x), in feet of the bamboo after x years.
Based on the equation, which statement best describes the rate of change in the context of the data.
The bamboo grows 3 feet every year.
The bamboo grows 0.3 feet every year.
The bamboo grows 4 feet every year.
The bamboo grows 0.4 feet every year.

12. Steve uses a movie rental service. There is a monthly fee of $10
Steve uses a movie rental service. There is a monthly fee of $10.00 and cost of $1.50 per movie rented.
Based on the equation, which statement is true.
The monthly fee is $1.50 and the amount per video is $10.00
The monthly fee is $10.00 and the amount per video is $1.50.
The monthly fee is $15.00 and the amount per video is $10.00.

13. Rip van Winkle has fallen asleep for a very long time
Rip van Winkle has fallen asleep for a very long time. The graph below describes the length of his beard in (mm) as a function of time (in weeks).
How long was Rip van Winkle’s beard when he feel asleep?
10 millimeters

14. Rip van Winkle has fallen asleep for a very long time
Rip van Winkle has fallen asleep for a very long time. The graph below describes the length of his beard in (mm) as a function of time (in weeks).
Rip van Winkle’s beard grew by 5 millimeters every _________ weeks.
2.5

15. Number of elapsed hours Temperature (in degrees F)
On a very cold night in Salisbury the weather person created the table below.
Number of elapsed hours
Temperature (in degrees F) 20 2 15 4 10 6 5 8 -5
What is the rate of change represent in the context of the problem?
-5 degrees every 2 hour
-2.5 degrees every hour

16. Number of elapsed hours Temperature (in degrees F)
On a very cold night in Salisbury the weather person created the table below.
Number of elapsed hours
Temperature (in degrees F) 20 2 15 4 10 6 5 8 -5
What does the y-intercept represent in the context of the problem?
20 at the time the weather person started recording the temperature

17. Number of elapsed hours Temperature (in degrees F)
On a very cold night in Salisbury the weather person created the table below.
Number of elapsed hours
Temperature (in degrees F) 20 2 15 4 10 6 5 8 -5
What does the x-intercept represent in the terms of the context?
After 8 hours the temperature is 0 F.

18. According to the graph, how long did Sarah stay at the beach?
Sarah drove from her house to the beach. She stayed at the beach and then drove back to her house. The graph shows this relationship.
According to the graph, how long did Sarah stay at the beach?
4 hours

19. Sarah drove from her house to the beach
Sarah drove from her house to the beach. She stayed at the beach and then drove back to her house. The graph shows this relationship.
According to the graph, what was Sarah’s average speed while drive to her house from the beach?
50 miles per hour

20. The graph below shows how the price of a certain type of cell phone has changed over time.
Between which months was the price of the cell phone increasing?
O to 3 months

21. The graph below shows how the price of a certain type of cell phone has changed over time.
Between which months was the price of the cell phone decreasing?
3 to 5 months

22. What questions do you have about this material?