Name _______________________________________ Date __________________ Class __________________ Review Exponents & Logarithms Identify whether the following is growth or decay, the values for a and b and the y intercept. 1.j(x) 2(0.5)x 2. p(x) 4(1.4)x ________________________________________ ________________________________________ Solve. 3. A certain car depreciates about 15% each year. a. Write a function to model the depreciation in value for a car valued at $20,000. ________________________________________ b. Graph the function. c. Suppose the car was worth $20,000 in 2005. What is the first year that the value of this car will be worth less than half of that value? ________________________________________ Identify the inverse of the following functions. 4.f (x ) 5x 2 ________________________ 7. f ( x ) x 12 ________________________ 5. f (x ) x 6 ________________________ 8. f ( x ) x 12 4 ________________________ 6. f ( x ) x 1 2 ________________________ 9. f ( x ) 3x 1 6 ________________________ Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 2 Name _______________________________________ Date __________________ Class __________________ Graph each function. Then write and graph its inverse. 10. f (x ) 2x 4 11. ________________________________________ f (x) 5 x 2 2 ________________________________________ Write each exponential equation in logarithmic form. 12. 3 7 2187 13. 12 2 144 ________________________ ________________________ 14. 5 3 125 ________________________ Write each logarithmic equation in exponential form. 15. log10 100,000 5 16. log4 1024 5 ________________________ ________________________ 17. log9 729 3 ________________________ Evaluate by using mental math. 18. log 1,000,000 19. log 10 ________________________ ________________________ 20. log 1 ________________________ Use the given x-values to graph each function. Then graph its inverse. Describe the domain and range of the inverse function. 21. f (x ) 2 x ; x 2, 1, 0, 1, 2, 3, 4 Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 2 Name _______________________________________ Date __________________ Class __________________ Express as a single logarithm. Simplify, if possible. 22. log6 8 log6 27 ________________________ 25. log2 1920 log2 30 ________________________ 23. log3 6 log3 13.5 24. log4 32 log4 128 ________________________ 26. log3 486 log3 2 ________________________ 27. log6 180 log6 5 ________________________ ________________________ Simplify, if possible. 28. log4 16 ________________________ 29. log2 8 x+12 30. 7log7 30 ________________________ ________________________ Solve. 31. 35x 272x + 1 ________________________ 34. 163x 64x + 9 ________________________ 37. log x log 9 3 ________________________ 32. 36x + 2 64x 33. 55x - 6 50 ________________________ 35. 81x 243x + 2 ________________________ 1 36. 2 ________________________ 38. log x log 4 1 3x 82 ________________________ 39. log (x 6) log(5x 2) ________________________ ________________________ Solve. 40. Halle deposited $4000 into an account that earns 5% interest each year. The growth of her investment can be expressed by the exponential equation A 4000 (1 0.05)t, where A is the amount in the account after t years. In how many years will her account exceed $10,000? ________________________________________________________________________________________ From the question above – what is the amount Halle will have, after the same number of years if the compounding is: a. Quarterly b. Daily c. Continuous Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 2 Name _______________________________________ Date __________________ Class __________________ Write each transformed function. 41. The function f (x) log x is reflected across the y-axis. 42. The function f (x) 8x is vertically stretched by a factor of 2. 43. The function f (x) 3x is moved left 4 units and two units down. 44. The function f (x) ln x is shifted 3 units right and reflected across the x-axis. a. Write the function that is shifted 3 units right. b. Take your answer to part a and write a function that reflects it across the x-axis. Given the parent function f(x) = 2x : state the transformation, the y intercept and the asymptote of the new function. 45. g(x) = 2x – 3 46. g(x) = 2x+4 47. g(x) = -3*2x Given the parent function f(x) = log x : state the transformation and the asymptote of the new function. 48. g(x) = log x + 2 49. g(x) = log (x+2) 50. g(x) = -3*log x Simplify. 51. ln ex + 2 ________________________ 3x + 1 54. ln e ________________________ 52. eln 2x ________________________ 55. ln e ________________________ 53. e7 ln x ________________________ 56. ln e2x + y ________________________ Solve. 57. Use the formula A P ert to compute the total amount for an investment of $4500 at 5% interest compounded continuously for 6 years. ________________________________________________________________________________________ Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 2 Name _______________________________________ Date __________________ Class __________________ Answers: 1.Decay, a= - 2 , b = .5 , y intercept = - 2 2. Growth, a = 4 , b = 1.4 , y intercept = 4 20,000( 0.85)x 3. a. y b. c. 2010 4. f 1(x) x2 5 7. f (x) 12x 9. f 1 x 5. f 1(x) x 6 6. f 1(x) x 1 2 8. f 1(x) 4x 12 6x 1 1 , or f 1 x 2x 3 3 10. f 1 x 1 x2 2 Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 2 Name _______________________________________ Date __________________ Class __________________ 11. f 1 x 2 x 2 5 12. log3 2187 7 13. log12 144 2 14. log5 125 3 15. 10 100,000 16. 4 1024 17. 93 729 5 18. 6 5 19. 1 20. 0 21. Domain: {x|x 0}; range: all real numbers 22. log6 216 3 23. log3 81 4 24. log4 4096 6 25. log2 64 6 26. log3 243 5 27. log6 36 2 28. 0 29. 3x 30. 30 32. x 33. x 1.686 31. x 3 34. x 9 35. x 37. x 9000 38. x 2 10 2.5 36. x 39. x 2 2 40. 19 years a. $10282.11 b. $10322.45 c. $10342.84 41. g(x) log ( x) 42. g(x) 2(8)x Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 2 Name _______________________________________ Date __________________ Class __________________ 43. g(x) 3x+4 - 2 44. a. g(x) ln (x - 3) b. g(x) ln (x - 3) 45. Down 3, -2, -3 46. Left 4, 16, 0 47. Reflected across x & Vert Stretch by 3, -3, 0 48. Up 2, 0 49. Left 2, -2 50. Reflected across x & Vert Stretch by 3, 0 51. x 54. 3x 52. 2x 55. 1 53. x7 56. 2x y 57. $6074.36 Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 2