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. 32x+3x−2=0
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
Solving Exponential and Logarithmic Equations
Problem 51
Textbook Question
Solve each logarithmic equation in Exercises 49–92. Be sure to reject any value of x that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. ln x=2
Verified step by step guidance1
Recognize that the equation is given as \(\ln x = 2\), where \(\ln\) denotes the natural logarithm, which is the logarithm with base \(e\) (Euler's number).
Rewrite the logarithmic equation in its equivalent exponential form. Recall that if \(\ln x = 2\), then \(x = e^2\).
Express the solution as \(x = e^2\), which is the exact form of the answer.
Check the domain of the original logarithmic function. Since \(\ln x\) is defined only for \(x > 0\), verify that \(e^2\) is positive, which it is, so no values are rejected.
If a decimal approximation is needed, use a calculator to evaluate \(e^2\) and round the result to two decimal places.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Properties of Logarithms
Understanding the natural logarithm function ln(x) is essential, where ln(x) is the logarithm base e. Key properties include ln(e) = 1 and the ability to rewrite logarithmic equations in exponential form, such as ln(x) = 2 becoming x = e^2.
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Domain of Logarithmic Functions
The domain of ln(x) is x > 0, meaning the argument inside the logarithm must be positive. When solving equations, any solution that results in a non-positive argument must be rejected to ensure the solution is valid within the function's domain.
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Graphs of Logarithmic Functions
Converting Between Logarithmic and Exponential Forms
Solving logarithmic equations often requires rewriting them in exponential form. For example, ln(x) = 2 can be rewritten as x = e^2, which allows direct computation of x. This conversion simplifies solving and interpreting logarithmic equations.
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Converting Standard Form to Vertex Form
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