Algebra 2
Quiz 8.1-8.3
Show all work and reasoning to receive full credit!
Name _____________________________________
Determine whether each equation represents exponential growth or exponential decay. What percent increase or decrease
does the function model?
1. y = 70(0.60)x ______________
2. y = 12(1.34)x _____________
Percent ________________
Percent _______________
Write an exponential equation whose graph passes through the given points.
3. (1, 5), (2, 10)
4. The bear population increases at a rate of 2% per year. There are 1573 bears this year. Write a function in the form y  ab x that
models the bear population. How many bears will there be in 10 yr?
5. A new truck that sells for $29,000 depreciates 12% each year. Write a function that models the value of the truck. Find the value of
the truck after 7 yr.
6. I-123 is used in thyroid scans. It has a half-life of 13.2 h. Write the exponential decay function for a 45-mg sample. Find the
amount remaining after 5 h.
7. Suppose you invest $5000 at an annual interest of 6.9%, compounded continuously. How much will you have in the account after
10 years?
Evaluate to four decimal places.
8. e2.4
Write in logarithmic form.
9. 62 = 36
Write in exponential form.
Evaluate.
Evaluate.
10. log2 128  7
11. log9 27
12. log 4
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