# Week 10 – Function Notation

What is a function again?

It is a special group that is a part of relations. This group only has one output for every input. This means that all functions are relations but not all relations are functions. An example of a function is how each person only has one biological father.

So what is function notation?

Well, it can be considered as the way we write functions. It is meant to be a precise way of giving information about a function. Instead of writing out the whole situation and the chance of people getting confused from the words presented. Also, this is to make the function simpler for the reader. To not mix up different functions, each one is given a name, and they are referred to a single letter.

How to write function notation?

While to start you are going to give the function a name. For my example, I am going to use the letter f. However, it can be any letter you want. The name of the function will look like this: f(x). The f(x) notation is another way of representing the y-value in a function, y = f(x). You can also label the y-axis as the f(x) axis when you are graphing.  Next, you add the formal to the end.