In Exercises 32–35, the graph of a logarithmic function is given. Select the function for each graph from the following options: f(x) = log x, g(x) = log(-x), h(x) = log(2-x), r(x)= 1+log(2-x)
Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
6. Exponential & Logarithmic Functions
Introduction to Logarithms
Problem 38
Textbook Question
Solve each equation. log1/3 (x+6) = -2
Verified step by step guidance1
Recall the definition of a logarithm: if \(\log_{a}(b) = c\), then it is equivalent to the exponential form \(a^{c} = b\).
Rewrite the given equation \(\log_{\frac{1}{3}}(x+6) = -2\) in exponential form using the base \(\frac{1}{3}\) and the exponent \(-2\): \(\left(\frac{1}{3}\right)^{-2} = x + 6\).
Simplify the expression \(\left(\frac{1}{3}\right)^{-2}\) by applying the negative exponent rule: \(\left(\frac{1}{3}\right)^{-2} = 3^{2}\).
Calculate \$3^{2}\( to get the value on the right side of the equation, then set it equal to \)x + 6$.
Solve for \(x\) by subtracting 6 from both sides: \(x = 3^{2} - 6\).
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Logarithmic Functions and Their Properties
A logarithmic function is the inverse of an exponential function. The expression log_b(a) = c means that b raised to the power c equals a. Understanding this relationship allows you to rewrite logarithmic equations in exponential form to solve for the variable.
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Graphs of Logarithmic Functions
Change of Base and Negative Logarithms
Logarithms with bases between 0 and 1, such as 1/3, produce negative values for inputs greater than 1. Recognizing how the base affects the sign and behavior of the logarithm is essential when solving equations involving fractional bases.
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Change of Base Property
Solving Logarithmic Equations by Exponentiation
To solve equations like log_b(x + 6) = -2, rewrite the equation in exponential form: x + 6 = b^{-2}. Then calculate the power and isolate x. This method transforms the logarithmic equation into a simpler algebraic equation.
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Solving Logarithmic Equations
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