MathIsimple

Logarithmic Functions & Properties

Master logarithmic functions, understand properties, learn change of base, and apply logarithms to solve real-world problems.

11th Grade
Functions
~60 min
🎮 Interactive Activity: Logarithm Value Calculator

Calculate the value of the logarithm!

Expression:

log_2(8) = ?
🎮 Interactive Activity: Logarithm Property Applier

Apply logarithm properties to expand or simplify!

Property: Product Rule

log_b(xy)

Result:

?
1. Logarithmic Function Definition

What is a Logarithmic Function?

A logarithmic function is the inverse of an exponential function. If y = bˣ, then x = log_b(y). The logarithmic function has the form f(x) = log_b(x), where b > 0, b ≠ 1 is the base.

Example 1: Basic Logarithmic Function

f(x) = log₂(x)

• Base: 2

• Domain: (0, ∞) - only positive numbers

• f(1) = log₂(1) = 0 (since 2⁰ = 1)

• f(2) = log₂(2) = 1 (since 2¹ = 2)

• f(8) = log₂(8) = 3 (since 2³ = 8)

Example 2: Relationship to Exponentials

If 2³ = 8, then log₂(8) = 3

• The logarithm answers: "2 to what power equals 8?"

• Answer: 3, because 2³ = 8

• Logarithms and exponentials are inverse functions

2. Logarithm Properties
3. Change of Base Formula
4. Natural Logarithm and Common Logarithm
5. Transformations of Logarithmic Functions
6. Real-World Applications
Frequently Asked Questions

Practice Time!

Practice Quiz
10
Questions
0
Correct
0%
Score
1
What is log₂(8)?
2
Simplify: log₃(9) + log₃(3)
3
What is log₅(1)?
4
Simplify: log₂(x) + log₂(y)
5
What is the domain of f(x) = log(x)?
6
Simplify: log₄(16) - log₄(4)
7
What is log₃(27)?
8
Simplify: 3log₂(x)
9
What is the base of the common logarithm?
10
If log₂(x) = 5, what is x?