Algebra 2 Review 8.1-8.3 Name __________________________________ Without graphing, determine whether each equation represents exponential growth or exponential decay. What percent of increase or decrease does the function model? 1. y = 0.5(1.67)x 2. y = 1.023(0.98)x Write an exponential equation y = abx whose graph passes through the given points. 3. (1, 10), (2, 25) 4. (2, 6), (4, 54) What percent of increase or decrease does the function model? 5. y = 0.1(1.7)x 6. y = 7.3(0.8)x 7. Mr. Anderson put $1000 into an account that earns 4.5% annual interest. The interest is compounded annually and there are no withdrawals. How much money will be in the account at the end of 30 years? 8. 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? Evaluate each expression to four decimal places. 9. e3 11. e 10. e1/4 5 12. You place $900 in an investment account that earns 6% interest compounded continuously. Find the balance after 5 years. 13. 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. Write each equation in exponential form. 14. log4256 = 4 15. log8 1 2 64 16. log17289 = 2 17. log 1000 = 3 20. 29 = 512 21. 6-3 = Write each equation in logarithmic form. 18. 92 = 81 19. 10-3 = 0.001 1 216 Evaluate each logarithm. SHOW ALL WORK AS WE LEARNED IN CLASS!!! 22. log8 32 23. log 25 125 24. log432 25. log 9 1 27