2. Tell whether the equation or graph represents an exponential growth or exponential decay function.

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1 Name: Date: Period: ID: 1 Unit 9 Review Eponents & Logarithms NO GRAPHING CALCULATOR 1. Under each function, write es if it is an eponential function. If the answer is no, write an eplanation wh not. a) 3 b) 23 c) 2 d) Tell whether the equation or graph represents an eponential growth or eponential deca function. a) 0.24 b) 0.5 c) 3 d) 2 3. Give the percent increase or percent decrease for each equation. a) b) c) d) Sketch the graph of each eponential function b doing the following: Sketch the asmptote, label at least three distinct coordinate points on each graph, and write the domain and range of each function Domain: Range: Domain: Range: Domain: Range: Domain: Range:

2 Simplif. Your answer should contain onl positive eponents. 8. Write each equation in eponential form log log ID: 1 Write each equation in logarithmic form. Evaluate each epression log log 1 Sketch the graph of each eponential function b doing the following: Sketch the asmptote, label at least two distinct coordinate points on each graph, and write the domain and range of each function. 16. log log 1 3 Domain: Range: Domain: Range:

3 Name: Date: Period: ID: 1 Unit 9 Review Eponents & Logarithms (part 2) GRAPHING CALCULATOR ALLOWED For 18 21, use a calculator to evaluate the epression. Round the result to three decimal places log ln Epand ln 23. Condense to a single logarithm: 2log log log 24. Use a calculator to approimate log 9 to three decimal places. Show our work b using the change of base formula. For 25 29, solve each equation. If necessar, round answers to three decimal places log log

4 On the test, there will be four or five application problems chosen from the following tpes of problems: 30. Dennis just inherited $10,000 from a distant relative who passed awa. After spending $2,000 on new tank tops, he puts the rest into a savings account that earns 4.5% interest compounded monthl. How much mone will he have after 5 ears? (ou have to memorize the formula!) 31. You have discovered a new species of rodent which originates from upstate New York. It is a disgusting and filth animal that is ver difficult to eradicate, therefore it has been named Timkelliounous. This animal s population increases b 68% ever ear. How man Timkelliounouses will there be after 5 ears if the current population is 100? 32. The value of a new car purchased for $20,000 decreases b 10% per ear. Write an eponential deca model for the value of the car. Use the model to estimate the value after 4 ears. 33. Audre just won the mega millions lotter! She decided to take a lump sum pament of $250 million dollars. While thinking about what to do with the mone, she wondered how much she could earn from the interest each ear if it was all put into a savings account that compounded continuousl. She found an account that would pa 2.25% interest. How much interest will she gain after one ear? 34. The area of a wound decreases eponentiall with time. The area of a wound after das can be modeled b. where is the initial wound area. If the initial would area is 3 square centimeters, what is the area after 10 das?

5 35. The magnitude of an earthquake can be modeled b.. where is the amount of energ released (in ergs). During Mr. Bean s senior ear in high school, he woke up to an earthquake that released ergs. Mr. Bean s skis actuall fell off the wall and he thought there was a monster truck outside his bedroom window seriousl it was scar! What was the magnitude of this earthquake? 36. The decibel level of a sound is given b where I is the intensit of the sound measured in watts per square meter. a) What is the decibel level of a police siren if the sound intensit is watts per square meter? b) If an NBA arena has a decibel level (db) of 120. What is the sound intensit? How man times greater is that sound than a police siren (from part a)? 37. Recall from our notes on 9.6 the formula for Newton s Law of Cooling: Mr. Wilson s car just overheated on the drive home from work and is stuck on the side of the road. It overheated at 300 F and can be driven again at 230 F. If and it is 65 F outside, how long (in minutes) does Mr. Wilson have to wait until he can continue driving? 38. If ou have $1,000 in an account that pas 5% annual interest compounded continuousl, how long (in ears) would ou have to wait for that $1,000 to become $5,000?

6 1. a) No. The variable must be in the eponent, not the base. Answer Ke to Unit 9 Review (ID: 1) b) No. The base,, must be a positive number other than one. c) Yes. d) Yes. 2. a) Growth b) Growth c) Deca d) Deca 3. a) 13% increase b) 6.2% decrease c) 245% increase d) 4.5% decrease (1, 6) (0, 3) (-1, 3/2) (-3, 7) (-2, 4) (-1, -8) (-1, 3) (0, 2) (1, 4/3) (-3, 1) (-2, 2.5) (-4, -2) Domain: Range: Domain: Range: Domain: Range: Domain: Range: All real # s 0 All real # s 8 All real # s 0 All real # s log log log log (-1, 1) (-3, 0) (-1, 1) (2, 3) Domain: Range: Domain: Range: 22. ln ln 4 All real # s 1 All real # s 23. log $10, ,338 rodents , Value after four ears: $13, $5,688, square cm magnitude 36 a. 105 db 36 b. Sound Intensit: 1 watt per square meter How man times greater: times more intense! minutes ears