Mathematics
Grade 12
15 min
Product property of logarithms
Product property of logarithms
What you'll learn
- Count aloud to 10 with accuracy.
- Match a written number (1-10) to a group of the same number of objects.
- Show a number (1-10) using fingers when asked.
- Draw a picture to represent a number between 1 and 5.
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
State the product property of logarithms from memory.
Expand a single logarithm of a product into a sum of two or more logarithms.
Condense a sum of logarithms with identical bases into a single logarithm.
Apply the product property to simplify and solve logarithmic equations.
Verify potential solutions to logarithmic equations and discard extraneous roots.
Differentiate the correct application of the product property from common algebraic misconceptions.
Combine the product property with other logarithmic properties (e.g., power property) to manipulate complex expressions.
How can we turn a complex multiplication problem, like calculating the intensity of multiple sound sources, into a simple addition problem? 🤯 Logarithms hold the key!
This tutorial...
2
Key Concepts & Vocabulary
TermDefinitionExample
LogarithmThe exponent to which a specified base must be raised to obtain a given number. It answers the question: 'What exponent do I need?'log₂(8) = 3, because 2³ = 8.
BaseThe number that is being raised to a power in an exponential expression, or the subscript in a logarithmic expression.In log_b(x), 'b' is the base.
ArgumentThe value or expression inside the logarithm, on which the logarithmic function is operating. The argument must always be positive.In log₃(9x), '9x' is the argument.
Natural Logarithm (ln)A logarithm with the special base 'e' (Euler's number, approximately 2.718). It is written as ln(x) instead of log_e(x).ln(e²) = 2.
ExpandTo use logarithm properties to rewrite a single, complex logarithm as a sum,...
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Core Formulas
Definition of a Logarithm
log_b(x) = y <=> b^y = x
This is the fundamental relationship that allows conversion between logarithmic and exponential forms. It's essential for solving logarithmic equations.
Product Property of Logarithms
log_b(M * N) = log_b(M) + log_b(N)
The logarithm of a product of two or more positive numbers is equal to the sum of the logarithms of those numbers. This rule requires that all logarithms have the same base 'b'.
Product Property (Natural Log)
ln(M * N) = ln(M) + ln(N)
This is a specific application of the product property for the natural logarithm (base e). It functions identically to the general rule.
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Challenging
Solve for x: log₆(x + 5) + log₆(x) = 2
A.x = -9, 4
B.x = 4
C.x = -9
D.x = 7
Challenging
Solve for x: log(x) + log(x - 21) = 2
A.x = 25
B.x = -4, 25
C.x = -4
D.x = 100
Challenging
If log_b(P) = 2 and log_b(Q) = 3, what is the value of log_b(P²Q)?
A.12
B.10
C.6
D.7
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Frequently asked questions
What grade level is "Product property of logarithms"?
Product property of logarithms is a Grade 12 Mathematics lesson on ExcelOS.
What will I learn in Product property of logarithms?
You'll be able to: Count aloud to 10 with accuracy; Match a written number (1-10) to a group of the same number of objects; Show a number (1-10) using fingers when asked.
Is "Product property of logarithms" free to practice?
Yes. You can read the tutorial preview for free, and signing up for a free ExcelOS account unlocks the full tutorial and all practice questions with instant feedback.
How many practice questions are included with Product property of logarithms?
This lesson includes 25 practice questions across multiple difficulty levels, each with instant feedback and explanations.