Unit 34 Test Study Guide (Exponential & Logarithmic Functions) Name: __________________________________________ Date: ____________________________ Per: __________ Topic 1: Graphing Exponential & Logarithmic Functions Directions: Graph each function, then identify its key characteristics. 1. f ( x) 1 3 x 1 4 Domain: Range: y-intercept: Asymptote: Increasing Interval: Decreasing Interval: End Behavior: 2. f ( x) 2 2( x e 3 1) 5 Domain: Range: y-intercept: Asymptote: Increasing Interval: Decreasing Interval: End Behavior: 3. f ( x) 3 2 ( x 2) 6 Domain: Range: y-intercept: Asymptote: Increasing Interval: Decreasing Interval: End Behavior: © Gina Wilson (All Things Algebra®, LLC), 2017 Topic 2: Exponential vs. Logarithmic Form Directions: Graph each function, then identify its key characteristics. 4. f ( x) log3 ( x 4) 2 Domain: Range: x-intercept: Asymptote: Increasing Interval: Decreasing Interval: End Behavior: 5. f ( x) log 1 3( x 1) 1 Domain: 2 Range: x-intercept: Asymptote: Increasing Interval: Decreasing Interval: End Behavior: 6. f ( x) 7 ln( x) 3 4 Domain: Range: x-intercept: Asymptote: Increasing Interval: Decreasing Interval: End Behavior: © Gina Wilson (All Things Algebra®, LLC), 2017 Topic 3: Evaluating Logarithms Directions: Rewrite each equation in exponential form. 8. log 1 32 5 7. log3 81 4 9. ln 8 2.08 2 Directions: Rewrite each equation in logarithmic form. 7 11. e4 54.6 10. 4 2 128 12. 104 10, 000 Directions: Evaluate the following. Use the change of base formula when necessary. 14. log 1 625 13. log4 1 5 15. log12 6 16. log8 61 Topic 4: Properties of Logarithms, Condensing & Expanding Logarithms Directions: Condense each expression into a single logarithm. 1 17. 4 log3 x 2 log3 y 18. (log7 64 3 19. 1 ln 64 2 5 ln k 4 ln m 20. 2 log( x 2 log7 27) 4) log(3 x) Directions: Expand each logarithm completely. 21. log2 3 4 x 5 22. log4 3a7 c 5 © Gina Wilson (All Things Algebra®, LLC), 2017 5 u 23. log w2 24. ln(3 x2 3 2 x 8) Topic 5: Solving Logarithmic Equations Directions: Solve each equation, rounding to the nearest the-thousandths place when necessary. Check for extraneous solutions. 26. log9 12 log9 (k 5) log9 (k 6) 25. log(3 x2 4 x) log(2 x2 12) 27. 1 log5 (5c 9) 2 29. ln(2 r 3) log5 3 log5 2 1 ln 9 2 7 28. log8 (7 5 w) 30. 3 log6 (2h2 11 3 2 14h) 9 15 Topic 6: Solving Exponential Equations Directions: Solve each equation, rounding to the nearest the-thousandths place when necessary. Check for extraneous solutions. 31. 1 2 2 43 d 1 32. 243 1 9 u 27 5u © Gina Wilson (All Things Algebra®, LLC), 2017 33. 183 n 4 35. 5 7 92 r 49 7 34. 20 6 ex 36. 52 x 1 2 5 3x 7 144 Topic 7: Applications (Exponential Growth & Decay, Logistic Growth, Compound Interest) 37. Kevin started his new job with a salary of $26,550. Every year, he receives a 3.15% increase in his salary. Write and use a continuous exponential growth function to find his salary after 20 years. 38. A 2018 Chevy Tahoe was purchased for $62,625. After 5 years, the vehicle has a value of $35,000. Write and use a continuous exponential decay function to find the rate of depreciation. 39. A contagious disease started to spread around an apartment complex. After t days, the number of people who have been infected by the disease is modeled by the function below. Using the function, determine how many days it will take for 150 people to become infected. f (t ) 350 1 4e 0.07t © Gina Wilson (All Things Algebra®, LLC), 2017 40. Sharon invests $2,300 into an account that earns 4.25% interest compounded weekly. Assuming there are no other deposits or withdrawals, find the balance in the account after 18 years. Topic 8: Nonlinear Regression 41. On January 1, 2013, a deposit of $600 was made into a new investment account. The table below shows the balance of the account on the first of each successive year, and no other deposits or withdrawals were made. Use exponential regression to model the data, then determine what year the account will earn $4,000. Year Balance 2013 $600.00 2014 $675.11 2015 $771.64 2016 $865.79 2017 $980.26 42. The table below shows the gym membership sales in each of its first six weeks. Use logarithmic regression to write an equation to model the data, then find the number of gym memberships sold in the 20 weeks. Weeks Members 1 162 2 187 3 199 4 211 5 220 43. A population of fish is deposited into a local lake. Determine whether an exponential or power model best fits the data, then use the equation to approximate the number of fish after one-half of a year. Weeks Population 1 78 2 92 3 100 4 106 5 113 6 118 © Gina Wilson (All Things Algebra®, LLC), 2017