Logarithmic Functions
Objectives Write equivalent forms for exponential and logarithmic equations. Use the definitions of exponential and logarithmic functions to solve equations.
Solve for x. 10x = 1,000 10x = 1 . 1,000 10x = 85 To solve, a logarithm is needed.
Equivalent Exponential and Logarithmic Forms For any positive base b, where b ≠ 1: bx = y if and only if x = logby.
Exponential Form Logarithmic Form 103 = 1,000 log101,000 = 3
Write in logarithmic form. 2. 1. 54 = 625
Write in exponential form 1. log100.1 = -1 2.
One-to-One Property of Exponents If bx = by, then x = y.
Find the approximate value of each logarithmic expression.
Solve each equation for x. Round to the nearest hundredth. 2. 3.
Find the value of v in each equation. 1. v = log10 0.01 2. 2 = log7 v
Find the value of v in each equation. 3. 4.
HOMEWORK Worksheet