Function Notation

What is Function Notation?

Function notation is used as a more convenient way to name a function so that it can be more easily referenced.

We are normally used to seeing equations in the following form 

In this instance y is the function of x.  

In order to put this equation in function notation it is easiest to think of giving the word function a name in the equation. In the following example we will use "f".

For this equation the input is "x" and the output is simply f(x), instead of y.

Evaluating with Function Notation

If you are using function notation and need to substitute input values in to determine output values, you must substitute the input value in the equation for the given variable. In this case, x.

Ex. 

x=-1

Additional helpful Information

"f" is only one of many function names and "x" is only one example of a letter used for the independent variable. You can use any letters for either. 

For instance, we could use "k" as the function name and "s" as the independent variable for the equation above and it would appear like the following example.

If you still are having trouble with function notation I suggest the following youtube clip. It gives you a breif description of what function notation is and what it looks like. It also takes you through a few example problems to further your understanding of the process of using function notation.