In Exercises 39–40, graph f and g in the same rectangular coordinate system. Use transformations of the graph of f to obtain the graph of g. Graph and give equations of all asymptotes. Use the graphs to determine each function's domain and range. f(x) = ln x and g(x) = - ln (2x)
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 45
Textbook Question
Graph f(x) = (1/2)x and g(x) = log1/2 x in the same rectangular coordinate system.
Verified step by step guidance1
Identify the functions to be graphed: \(f(x) = \left(\frac{1}{2}\right)^x\) is an exponential function with base \(\frac{1}{2}\), and \(g(x) = \log_{\frac{1}{2}}(x)\) is the logarithmic function with base \(\frac{1}{2}\).
Recall that the graph of \(f(x) = a^x\) where \$0 < a < 1\( is a decreasing exponential curve that passes through the point \)(0,1)$ because any nonzero number raised to the zero power is 1.
For \(g(x) = \log_a(x)\) where \$0 < a < 1\(, the graph is the inverse of the exponential function \)f(x) = a^x\(. This means the graph of \)g(x)\( is a reflection of \)f(x)\( across the line \)y = x$.
Determine key points for \(f(x)\) by substituting values such as \(x = -1, 0, 1, 2\) to get points like \((x, f(x))\). Similarly, find points for \(g(x)\) by choosing \(x\) values and calculating \(g(x)\), keeping in mind the domain of \(g(x)\) is \(x > 0\).
Plot the points for both functions on the same coordinate system, draw smooth curves through these points, and include the line \(y = x\) to visualize the reflection relationship between \(f(x)\) and \(g(x)\).
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Exponential Functions
An exponential function has the form f(x) = a^x, where the base a is a positive constant. In this question, f(x) = (1/2)^x represents exponential decay since the base is between 0 and 1. Understanding how the graph behaves, including its asymptote and decreasing nature, is essential for plotting it accurately.
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Exponential Functions
Logarithmic Functions
A logarithmic function is the inverse of an exponential function and is written as g(x) = log_a(x), where a is the base. Here, g(x) = log_(1/2)(x) is the logarithm with base 1/2, which is less than 1, causing the graph to decrease and reflect the inverse behavior of the exponential function. Recognizing domain restrictions and shape is key.
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Graphs of Logarithmic Functions
Inverse Functions and Their Graphs
Exponential and logarithmic functions with the same base are inverses, meaning their graphs are reflections across the line y = x. Understanding this relationship helps in graphing both functions on the same coordinate system and predicting their intersection and symmetry properties.
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Graphs of Logarithmic Functions
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