Solve each equation. In Exercises 11–34, give irrational solutions as decimals correct to the nearest thousandth. In Exercises 35-40, give solutions in exact form. 52x + 3(5x) = 28
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 43
Textbook Question
Solve each equation. Give solutions in exact form. ln 4x = 1.5
Verified step by step guidance1
Identify the given equation: \(\ln 4x = 1.5\). This means the natural logarithm of \$4x\( equals \)1.5$.
Recall that the natural logarithm function \(\ln y\) is the inverse of the exponential function \(e^y\). To solve for \(x\), rewrite the equation in exponential form: \$4x = e^{1.5}$.
Isolate \(x\) by dividing both sides of the equation by 4: \(x = \frac{e^{1.5}}{4}\).
Express the solution in exact form, which involves leaving the answer in terms of \(e\) without approximating the value of \(e^{1.5}\).
Check the solution by substituting \(x\) back into the original equation to ensure the equality holds true.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Natural Logarithm (ln) Function
The natural logarithm, denoted as ln, is the inverse of the exponential function with base e. It answers the question: to what power must e be raised to get a given number? For example, ln(4x) = 1.5 means e raised to 1.5 equals 4x.
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Solving Exponential and Logarithmic Equations
To solve equations involving logarithms, rewrite the equation in exponential form to isolate the variable. For ln(4x) = 1.5, rewrite as 4x = e^{1.5}, then solve for x by dividing both sides by 4.
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Exact Form Solutions
An exact form solution expresses the answer without decimal approximations, often using constants like e or π. Here, the solution should be left as x = e^{1.5} / 4 rather than a decimal, preserving mathematical precision.
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