Pre-calculus Name__________________________________ Review #3 Chapter 4 Exponential and Logarithmic Functions Mrs. Spatola Pre-calculus 2009 In this chapter, you will be able to: Determine Whether a Function is One-to-One Obtain the Graph of the Inverse Function from the Graph of the Function Find an Inverse Function Evaluate Exponential Functions Define the Number e Change Exponential Expressions to Logarithmic Expressions Change Logarithmic Expressions to Exponential Expressions Evaluate Logarithmic Functions Determine the Domain of a Logarithmic Function Graph Logarithmic Functions Write a Logarithmic Expression as a Sum/Difference of Logarithms Write a Logarithmic Expression as a Single Logarithm Evaluate Logarithms Whose Base Is Neither 10 nor e Graph Logarithmic Functions Whose Base is Neither 10 nor e Solve Logarithmic Equations Solve Exponential Equations 1. Determine whether the function is one-to-one. 2. Decide whether or not the functions are inverses of each other. f(x) = 4x - 2, g(x) = 3. a) Find the inverse of f(x) = 2x + 3 b) Find the inverse of f ( x) 2x 1 x 1 4) Verify that f(x) = 2x + 3 and f (x) = ½(x - 3) are inverses of each other 5) The graph of a one-to-one function is given. Draw the graph of the inverse function f-1. For convenience, the graph of y = x is also given. 6) The function f is one-to-one. State the domain and the range of f and f-1. f(x) = Domain: f(x) ____________________________ Range: f(x) _________________________ Domain f-1(x) ____________________________ Range: f-1(x) _______________________ 7) Define the number e and give its approximate numerical value. 8) State the domain and range, x-intercepts; y-intercept, asymptote(s) : a) f(x) = ax, a > 1 b) f(x) = ax, 0 < a < 1 9) Determine whether the given function is exponential or not. If it is exponential, identify the value of the base a. 10) Determine the exponential function whose graph is given. f(x) = ________________ 11) Change the exponential expression to an equivalent expression involving a logarithm. a) 72 = 49 b) ex = 6 12) Change the logarithmic expression to an equivalent expression involving an exponent. a) log3 b) ln = -3 = -2 13) Find the domain of the Log Function a) f(x) = log2(1 – x) b) g(x) = log5( 1 x ) 1 x x 2 1 ) as a sum of logarithms. Express all powers as factors. 14) a) Write log a(x x2 b) Write log a( ) as a difference of logarithms. Express all powers as factors. ( x 1) 3 c) Write log a( x3 x2 1 ) as a difference of logarithms. Express all powers as factors. ( x 1) 4 15) Condense the logarithmic expression. a) loga7 + 4loga3 c) 2ln(x+2) - lnx b) 1 log x 3 log ( x 1) 10 2 10 16) Evaluating logarithms whose base is neither 10 or e. a) Evaluate log107 c) Evaluate log 2 b) Evaluate log589 5 17) Solving Simple Exponential and Logarithmic Equations a) 2 x 32 b) log 10 x 1 c) log 3 (4 x 7) 2 d) 2 log 5 x log 5 9 f) 3 x 1 81 e) log 4 ( x 3) log 4 (2 x) 1 g) 5 x 2 33x 2 h) e x + i) loga(x-1) – loga(x+6) = loga(x-2)-loga(x-3) 3 = πx 18) Fill in the blank. a) If every horizontal line intersects the graph of a function f at no more than one point, then f is a(n) _______________________________________function. b) If f--1 denotes the inverse of a function f, then the graphs of f and f -1 are symmetric with respect to the line ____________________________________. c) The graph of every exponential function f(x) = ax , a > 0, a ≠ 1, passes through the two points __________________________________. d) The logarithm of a product equals the ____________________________ of the logarithms. e) For every base, the logarithms of _____________________________equals 0. f) The domain of the logarithmic function f(x) = loga x consists of ______________________. g) The graph of every logarithmic function f(x) = loga x, a > 0, a ≠ 1, passes through the two points _____________________________________.