Solve each exponential equation in Exercises 23–48. Express the solution set in terms of natural logarithms or common logarithms. Then use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. 5^x=17
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- 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
Solving Exponential and Logarithmic Equations
Problem 30
Textbook Question
Graph f(x) = 2^x and g(x) = log2 x in the same rectangular coordinate system. Use the graphs to determine each function's domain and range.
Verified step by step guidance1
Understand the functions: f(x) = 2^x is an exponential function with base 2, and g(x) = log₂(x) is a logarithmic function with base 2. These two functions are inverses of each other.
Graph f(x) = 2^x: Start by creating a table of values for x and f(x). For example, calculate f(x) for x = -2, -1, 0, 1, and 2. Plot these points on the coordinate plane and draw a smooth curve passing through them. Note that the graph will pass through (0, 1) and approach the x-axis as x approaches negative infinity, but it will never touch the x-axis.
Graph g(x) = log₂(x): Create a table of values for x and g(x). For example, calculate g(x) for x = 1/4, 1/2, 1, 2, and 4. Plot these points on the coordinate plane and draw a smooth curve passing through them. Note that the graph will pass through (1, 0) and approach the y-axis as x approaches 0 from the right, but it will never touch the y-axis.
Determine the domain and range of f(x): The domain of f(x) = 2^x is all real numbers (-∞, ∞), because you can raise 2 to any real number power. The range is (0, ∞), because the output of 2^x is always positive.
Determine the domain and range of g(x): The domain of g(x) = log₂(x) is (0, ∞), because you can only take the logarithm of positive numbers. The range is all real numbers (-∞, ∞), because the logarithmic function can produce any real number as an output.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Exponential Functions
Exponential functions, such as f(x) = 2^x, are mathematical expressions where a constant base is raised to a variable exponent. These functions exhibit rapid growth as x increases and approach zero as x decreases. The domain of an exponential function is all real numbers, while the range is limited to positive values, indicating that the output never reaches zero.
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Logarithmic Functions
Logarithmic functions, like g(x) = log2 x, are the inverses of exponential functions. They answer the question of what exponent a base must be raised to in order to produce a given number. The domain of a logarithmic function is restricted to positive real numbers, while the range encompasses all real numbers, reflecting that logarithms can yield any real value.
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Graphs of Logarithmic Functions
Graphing Functions
Graphing functions involves plotting points on a coordinate system to visualize their behavior. For f(x) = 2^x, the graph will show exponential growth, while g(x) = log2 x will illustrate a gradual increase that approaches infinity. Understanding how to graph these functions helps in determining their domains and ranges, as well as their intersections and asymptotic behavior.
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