Solve each equation. Give solutions in exact form. ln 4x = 1.5
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 47
Textbook Question
Solve each equation. Give solutions in exact form. log6 (2x + 4) = 2
Verified step by step guidance1
Recall the definition of logarithm: if \(\log_b A = C\), then it is equivalent to the exponential form \(b^C = A\). Here, the base is 6, the logarithm equals 2, and the argument is \$2x + 4$.
Rewrite the equation \(\log_6 (2x + 4) = 2\) in exponential form: \$6^2 = 2x + 4$.
Calculate \$6^2\( (which is \)6\( raised to the power of \)2\() to simplify the right side of the equation, but do not finalize the numeric value; just write it as \)36$ for clarity.
Set up the equation \$36 = 2x + 4\( and isolate the variable term by subtracting 4 from both sides: \)36 - 4 = 2x$.
Solve for \(x\) by dividing both sides of the equation by 2: \(\frac{36 - 4}{2} = x\). This gives the exact solution for \(x\).
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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 properties of logarithms, such as the definition log_b(a) = c means b^c = a, is essential. This allows converting logarithmic equations into exponential form to solve for the variable.
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Change of Base Property
Solving Exponential Equations
Once the logarithmic equation is rewritten in exponential form, solving for the variable involves algebraic manipulation, such as isolating the variable and simplifying expressions.
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Solving Exponential Equations Using Logs
Domain Restrictions of Logarithmic Functions
Logarithmic functions are only defined for positive arguments. When solving, it is important to check that the solutions make the argument inside the log positive to ensure valid answers.
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Domain Restrictions of Composed Functions
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