Functions in math

What is a Function

A function relates an input to an output.

It is like a machine that has an input and an output.

And the output is related somehow to the input.

f(x)
"f(x) = ... " is the classic way of writing a function.
And there are other ways, as you will see!

Input, Relationship, Output

We will see many ways to think about functions, but there are always three main parts:

• The input
• The relationship
• The output

Domains, Codomains, and Ranges

Domain, Range and Codomain

Function composition in math

Composition of Functions