What is a Logarithm?

Definition

If a^x = b, then log_ab = x.

We say: log base a of b equals x. (a is the base, b is the argument.)

Examples

2³ = 8   ⇒   log₂8 = 3

10² = 100   ⇒   log₁₀100 = 2

5⁰ = 1   ⇒   log₅1 = 0

Special cases

log_aa = 1   (because a¹ = a)

log_a1 = 0   (because a⁰ = 1)

Note: The base a > 0 and a ≠ 1. The argument b > 0.

Discussion

How was the lesson? Discuss Lesson

Related Exercises