Unit 7: Exponential Functions Review

Unit 7: Exponential Functions Review Multiple-Choice: Identify the choice that best completes the statement or answers the question.

____ 1. Which equation corresponds to the graph shown? a. y = 2x + 2 b. y = – 2 c. y = 2x – 2 d. y = + 2

____ 2. What is the y-intercept on the graph shown in problem #1? a. b. 1 c. 0 d. –1

____ 3. TOURNAMENTS: A chess tournament starts with 16 people competing. The exponential function y = 16(1/2)x describes how many people are remaining in the tournament after x rounds. How many people are left in the tournament after 2 rounds? a. 4 b. 2 c. 8 d. 1

____ 4. INVESTMENTS: Determine the amount of an investment if $1000 is invested at an interest rate of 8% compounded quarterly for 2 years. a. $1160.00 b. $1171.66 c. $1040.40 d. $1166.40

____ 5. BIOLOGY: If y = 10(2.5)t represents the number of bacteria in a culture at time t, how many will there be at time t = 6? a. 2441 b. 244 c. 24 d. none

____ 6. DEPRECIATION: A $60,000 piece of machinery depreciates in value at a rate of 11% per year. About what will its value be in 5 years? a. $47,526 b. $42,298 c. $33,504 d. $37,645

____ 7. Look for a pattern in the table of values to determine which model best describes the data. x 0 1 2 3 y 1 10 100 1000 a. linear b. quadratic c. exponential d. none of these

____ 8. Which function best models the data in Question 19? a. y = 10x b. y = 10x2 c. y = 10x d. y = 10x + 1

____ 9. How is the graph of f(x) = 2x related to the graph of g(x) = 2x + 3? a. translated down 3 units c. Translated right 3 units b. translated up 3 units d. translated left 3 units

____ 10. Which equation represents exponential growth? a. y = 5( .84) x b. y = 5x c. y = 0.3x3 d. y = 5 (1.06) x

____ 11. A weightlifter can increase the weight W(x) that she can lift according to W(x) = 315(1.05)x , where x represents the number of training cycles completed. How much will she deadlift after 4 training cycles? a. 365 lb b. 383 lb c. 378 lb d. 402 lb

____ 12. BIOLOGY: A certain fast-growing bacteria increases 6% per minute. If there are 100 bacteria now, about how many will there be 12 minutes later? a. 172 b. 201 c. 48 d. 190

____ 13. POPULATION: A city’s population is about 954,000 and is decreasing at an annual rate of 0.1%. Predict the population in 50 years. a. 577,176 b. 906,300 c. 1,002,888 d. 907,450

____ 14. Look for a pattern in the table of values to determine which model best describes the data. x 0 1 2 3 Unit 7: Exponential Functions Review y 1 7 49 343 a. linear b. quadratic c. exponential d. none of these

____ 15. Which function best models the data in Question 19? a. y = 7x b. y = 7 x 2 c. y = 7 x d. y = 7 x + 1

Describe the translation of this graph from y = 2x, then graph each function. Find the y-intercept, and state the domain and range.

16. y = 2x+1

17. y = 2x + 1

18. y = -2x + 2

19. y = 2x-1 – 3

20. BIOLOGY: The population of bacteria in a petri dish increases according to the model p = 550(2.7)0.008t, where t is the number of hours and t = 0 corresponds to 1:00 PM. Use this model to estimate the number of bacteria in the dish at 5:00 PM.

21. Find the final value of $2,500 invested at an interest rate of 2% compounded monthly for 10 years.

22. COMPUTERS: Zita’s computer is depreciating at a rate of 3% per year. She bought the computer for $1,200. Write an equation to represent this situation. What will the computer’s value be after 5 years?

Look for a pattern in each table of values to determine which kind of model best describes the data. Then write an equation for the function that models the data.

23. x 0 1 2 3 4

y 0 3 12 27 48

24. x 0 1 2 3 4

y 1 2 4 8 16

25. x 0 1 2 3 4

y 0 -1 -4 -9 -16 Unit 7: Exponential Functions Review Chapter 10 Review Answer Section

MULTIPLE CHOICE

1. ANS: B PTS: 1

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25. ANS: D PTS: 1 Unit 7: Exponential Functions Review 26. ANS: A PTS: 1

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