Advanced Algebra Chapter 8 “Exponential and Logarithmic Functions and Relations” Date Day # Section Page Assignment 02/05 1 8.2 Solving Exponential Equations 8.3 Logarithms and Logarithmic Functions 488 496 1, 11, 14, 32, 35, 50-53 13, 15, 19, 23, 25, 29, 33, 65, 67, 70 02/08 2 Graphing Exponential and Logarithmic Equations -- 02/09 3 8.4 Solving Logarithmic Equations 504 02/10 4 QUIZ (8.2-8.4) -- 02/11 5 8.5 Properties of Logarithms 512 23-25, 39, 41, 69, 70, 71 02/12 6 8.5 Properties of Logarithms 512 8, 9, 11, 26, 45, 46, 47 02/16 7 8.6 Common Logs 519 17, 23, 25, 27, 33, 43, 45 8.7 Log Base e and Natural Logs 529 9, 11 Worksheet #2 9-19 (odd), 45, 48, 50, 52, 58, 59 Worksheet #4 02/17 8 8.8 Using Logarithmic and Exponential Equations -- Worksheet #8 02/18 9 QUIZ (8.2-8.8) -- Review Packet 02/19 10 CHAPTER 8 REVIEW -- Practice Test 02/22 11 TASK/N-Spire 02/23 12 CHAPTER 8 TEST TBA -- Cumulative Review All assignment keys and blank copies of worksheets are posted on my website. Assignments are subject to change. Advanced Algebra w/ Trig Notes 8.2 Goal: Students will be able to solve exponential equations Exponential Function: An equation of the form y a x , where a > 0 and a 1. There are 2 ways to solve for the exponent in an exponential function: 1. Force the bases to be equal, then if a x a y then x = y. 2. Logarithms – later this chapter Solve. 1. 93 3x 2 3. 16 2 x1 2. 34 27 x1 1 32 2x 1 x5 5 25 4. Advanced Algebra w/ Trig Notes 8.3 Goal: Students will be able to convert exponential to logarithmic equations and vice versa. Students will be able to evaluate logarithmic equations Solve. 1. 23 x 4x2 2. 8 x2 Exponential Equations: y a x 1 16 (spoken as y = a to the x) Logarithm: The “reverse” of an exponential expression, which helps us put really really big or small numbers on a more human- friendly scale. Logarithmic Equation: x log a y where a and y >0 (spoken as x = log base a of y) Put in logarithmic form. 1. 52 25 2. 105 100,000 3. 80 1 6. log1 1 7 7. log 2 10. log 27 3 11. log 1 4. 34 81 Put in exponential form. 5. log 2 32 5 1 4 16 8. log 9 3 Evaluate. 9. log8 64 4 1 64 12. log16 2 1 2 Advanced Algebra w/ Trig Notes Graphing GOAL: Students will be able to graph logarithmic functions and solve logarithmic functions by rewriting as an exponential function. Exponential Form y ax Logarithmic Form y log a x Inverse Functions Properties of Exponential Functions Properties of Logarithmic Functions Domain: Domain: Range: Range: x-intercepts: x-intercepts: y-intercept: y-intercept: Asymptotes: Asymptotes: Graph contains these points:_________________________ Graph contains these points: _________________________ Graph both on this: Graph using transformations. f ( x) ln( x 3) f ( x ) 3x f ( x) ln( x) f ( x) 2 x 1 f ( x) log( x) 2 y 2 x 3 Advanced Algebra w/ Trig Notes 8.4 Goal: Students will be able to solve logarithmic equations. Simplify. Solve. 1 3 7 1. 5n 4 10n 2 2 xy 24 x 2. 2 5 w w 3 Calculate in the calculator: log 4 log -4 log 100 log-100 log .5 What can you conclude? Solve. 1. log3 27 y 4. log9 x 3 2. log 7 1 y 49 5. log b 64 3 2 3. log 1 27 y 3 6. log16 x New Property: If logb x logb y , then x = y 7. log3 (3x 6) log3 (2 x 1) 8. log8 ( x 2 14) log8 (5 x) 3 2 log -.5 Advanced Algebra w/ Trig Notes 8.5 Goal: Students will be able to solve logarithmic equations. Properties of Logs: 1. logb m logb n logb m n m n 2. log b m log b n log b 3. log b m p p log b m 4. log b b 1 Rewrite the following expressions using a single logarithm. 1. log 2 x 4log 2 y 2. 3log x log 2 Solve. MUST CHECK ANSWERS! 1 3 3. log5 4 log5 x log5 36 4. 2 log 6 4 log 6 8 log 6 x 5. log3 6 log3 3 log3 x 6. log 6 ( x 2 3) log 6 ( x 1) log 6 7 Advanced Algebra w/ Trig Notes 8.5 Day 2 Goal: Students will be able to solve logarithmic equations. Solve. Simplify. 1. log7 x log7 x 1 log7 12 x2 9 4 2. 3 x 8 Solve. MUST CHECK ANSWERS! 1. log 4 ( x 2) log 4 ( x 4) 2 2. log5 y 12 log5 y 12 2 3. log5 x 5 log5 x 1 log5 x 1 4. log2 x log2 x 2 1 Advanced Algebra w/ Trig Notes 8.6 /8.7 Goal: Students will be able to evaluate common logarithmic expressions Common Log: log10 are called common logarithms (we usually write without the 10) Number e: an irrational number used in science and math e 2.718 Natural Log: ln, a log with number e as base (all properties of logs apply) loge e 1 so ln e = 1 Exponential Equation: an equation with a variable in the exponent Two ways to solve: 1. Force bases to be the same, set exponents equal 2. Take log (or natural log) of both sides Solve the equations. 1. 4 x 24 2. 8 4e5 x 3. 7 x 2 53 x 4. 3x 4 5 x 1 Change of Base Formula: log a n 5. log 4 22 log b n ln n log b a ln a 6. log12 95 7. log11 63 Advanced Algebra w/ Trig Notes 8.8 Goal: Students will be able to solve real world problems using exponential and logarithmic equations. Growth and Decay y nekt y – final amount n – initial amount k – g/d constant t – time Continuous Compounding A Pe rt A – total amount P – initial amount r – rate (decimal %) t – time in years Appreciation and Depreciation Vn P 1 r n Vn - new value P – initial value r – rate (decimal %) n – time in years Solve. 1. Radioactive isotopes decay with time. In 9 years, just half of the mass of a 20-gram sample of an isotope remains. This period of time is called the half-life of the isotope. Find the constant k for this isotope when t is given in years. 2. Zeller Industries bought a piece of weaving equipment for $50,000. It is expected to depreciate at a steady rate of 10% each year. When will the value have depreciated to $25,000? 3. The Saver’s Club at Citizen’s Fidelity Bank promises to double your money in 8.5 years. Assuming that the investment is compounded continuously, what is the interest rate?