LOGARITHM

Introduction to Logarithm

In its simplest form, a logarithm answers the question:

How many of one number do we multiply to get another number?

Example 1: 

How many 2s do we multiply to get 8?

Answer 

2 x 2 x 2 = 8 

so we needed to multiply 3 of the 2s to get 8.

So the logarithm is 3. 

How to Write it:

We write "the number of 2s we need to multiply to get 8 is 3" as:

log₂(8) = 3

Example 2:

What is log₅(625) ... ?

We are asking "how many 5s need to be multiplied together to get 625?"

5 × 5 × 5 × 5 = 625, so we need 4 of the 5s

Answer: log₅(625) = 4

Example 3:

What is log₂(64) ... ?

We are asking "how many 2s need to be multiplied together to get 64?"

2 × 2 × 2 × 2 × 2 × 2 = 64, so we need 6 of the 2s

Answer: log₂(64) = 6

Exercise:

What is log3(27) ... ?