Algebra 2
Review 8.1-8.3
Name __________________________________
Lesson 8.1
Without graphing, determine whether each equation represents exponential growth or exponential decay.
9 x
1. y = 10x
2. y = 0.5(1.67)x
3. y = 1.023(0.98)x
4. y = 2( 10
)
Write an exponential equation y = abx whose graph passes through the given points.
5. (1, 10), (2, 25)
6. (2, 128), (-1, 16)
7. (-2, 0.05), (2, 12.8)
What percent of increase or decrease does the function model?
8. y = 15(1.45)x
9. y = 0.32(.99)x
10. y = 0.1(1.7)x
11. y = 7.3(0.8)x
12. Mr. Anderson put $1000 into an account that earns 4.5% annual interest.
The interest is compounded continuously and there are no withdrawals.
How much money will be in the account at the end of 30 years?
13. A manufacturer bought a new rolling press for $48,000. It has depreciated in value at an annual rate of 15%.
What is the value 5 years after purchase?
Lesson 8.2
Graph each function.
14. y = 3x
15. y = 2(4)x
16. y = -1(2)x+2 + 3
Evaluate each expression to four decimal places.
17. e3
18. e1/4
19.
e
5
20. e-1
21. You place $900 in an investment account that earns 6% interest compounded continuously. Find the balance after 5 years.
22. I-123 is used in thyroid scans. It has a half-life of 13.2 hours. Write the exponential decay function for a 45-mg sample.
Find the amount remaining after 5 hours.
Lesson 8.3
Write each equation in exponential form.
23. log4256 = 4
24. log8
1
= -2
64
25. log17289 = 2
26. log36561 = 8
Write each equation in logarithmic form.
27. 92 = 81
28. 10-3 = 0.001
29. 29 = 512
30. 6-3 =
Evaluate each logarithm.
31. log216
32. log5125
33. log432
34.
State the parent function. Then explain the translation.
35. y = log3(x + 1)
36. y = log2x – 3
37. y = log4(x – 4) + 1
1
216
log1212