Name
9-3
Class
Date
Form K
Practice
Modeling Exponential Data
Identify the domain and range of the function. Express the range using an inequality.
1. 𝑓(𝑥) = 5 ∙ 2𝑥
2. 𝑓(𝑥) = 12 ∙ 0.10𝑥
3. 𝑓(𝑥) = −2.4 ∙ 8𝑥
4. 𝑓(𝑥) = −15 ∙ 0.5𝑥
5. 𝑓(𝑥) = −0.025 ∙ 16𝑥
6. 𝑓(𝑥) = 35 ∙ 7𝑥
Find 𝒇(𝟎), 𝒇(𝟐), 𝒇(−𝟑) for each function. Round to the nearest tenth.
7. 𝑓(𝑥) = 2 ∙ 1.5𝑥
8. 𝑓(𝑥) = 26 ∙ 0.25𝑥
9. 𝑓(𝑥) = −1.8 ∙ 3𝑥
10. 𝑓(𝑥) = −8.3 ∙ 0.4𝑥
11. 𝑓(𝑥) = 0.42 ∙ 5𝑥
12. 𝑓(𝑥) = −17 ∙ 1.6𝑥
Use the table at the right for problems 13-15.
The table shows the annual enrollment for a
high school that opened in 2000.
13. Which type of function best models the data?
14. Write an equation to model the data.
15. If this trend continues, predict the enrollment of the high school in 2015.
Pearson Texas Algebra I
Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.
Name
9-3
Class
Date
Practice (continued)
Form K
Modeling Exponential Data
Use the table at the right for problems 16-21. The
table shows the number of bacteria being grown
in a petri dish over a 4-week period.
16. What is an exponential model for this data?
17. What are the domain and range? Express the range using an inequality.
18. Use your equation to predict the number of bacteria at week 7.
19. How long will it take for the number of bacteria to grow to 400?
20. What is the y-intercept of the function in exercise 16, and what does it mean in the
context of the problem?
21. What are a and b in the function in exercise 16? What do a and b mean in the context of the
problem?
22. Open-Ended An exponential equation has the form 𝑓(𝑥) = 𝑎𝑏 𝑥 . Explain the meaning of the
function when 0 < 𝑏 < 1. Describe two situations in which a fractional b-value is realistic.
23. Reasoning Think about the equation 𝑓(𝑥) = 𝑎𝑏 𝑥 . What is the y-intercept? Explain.
Pearson Texas Algebra I
Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.