Use the change-of-base theorem to find an approximation to four decimal places for each logarithm. log√19 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
Properties of Logarithms
Problem 92
Textbook Question
Determine whether each equation is true or false. Where possible, show work to support your conclusion. If the statement is false, make the necessary change(s) to produce a true statement. ln(8x3) = 3 ln (2x)
Verified step by step guidance1
Recall the logarithmic property that states \(\ln(a^b) = b \ln(a)\), which allows us to rewrite logarithms of powers.
Rewrite the left side \(\ln(8x^3)\) by expressing 8 as \$2^3\(, so it becomes \)\ln(2^3 \cdot x^3)$.
Use the logarithm product rule: \(\ln(ab) = \ln(a) + \ln(b)\), to separate \(\ln(2^3 \cdot x^3)\) into \(\ln(2^3) + \ln(x^3)\).
Apply the power rule to each term: \(\ln(2^3) = 3 \ln(2)\) and \(\ln(x^3) = 3 \ln(x)\), so the left side becomes \$3 \ln(2) + 3 \ln(x)$.
Rewrite the right side \$3 \ln(2x)\( using the product rule: \)3 (\ln(2) + \ln(x)) = 3 \ln(2) + 3 \ln(x)$, and compare it to the left side to determine if the equation is true.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
2mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Properties of Logarithms
Logarithmic properties, such as the product, quotient, and power rules, allow us to simplify and manipulate logarithmic expressions. For example, ln(ab) = ln(a) + ln(b) and ln(a^n) = n ln(a). These rules are essential for breaking down and comparing logarithmic equations.
Recommended video:
Change of Base Property
Equivalence of Logarithmic Expressions
Two logarithmic expressions are equal if and only if their arguments are equal, assuming the logarithm base is the same and the arguments are within the domain. This concept helps verify if an equation like ln(8x^3) = 3 ln(2x) holds true by comparing the expressions inside the logarithms.
Recommended video:
Logarithms Introduction
Algebraic Manipulation of Exponents and Factors
Understanding how to factor and expand expressions with exponents is crucial. For instance, recognizing that 8x^3 = (2^3)(x^3) and that 3 ln(2x) = 3(ln 2 + ln x) helps in rewriting and comparing both sides of the equation accurately.
Recommended video:
Introduction to Exponents
Watch next
Master Product, Quotient, and Power Rules of Logs with a bite sized video explanation from Patrick
Start learningRelated Videos
Related Practice
Textbook Question
668
views
