Function Notation

Function notation is a common way to write equations. Function notation is written f(x) and read “f of x.” When we are dealing with functions it is enough to say y=f(x). y and f(x) are pretty much interchangeable, but there are few things that function notation allows us to do that a regular y doesn’t.

 

Another perk of using function notation is that you can plug things into the function really easily. If we want to find out when x=3 we will write f(3)

    \[\mathbf{f(x)=3x-1}\]

f(1)=3(1)-1

f(2)=3(2)-1

f(3)=3(3)-1

You can also plug in other variables. To plug these

  1. Put a set of parenthesis wherever x was
  2. Then plug your variable/expression into the parenthesis
  3. Simplify

What you plug into the equation, your x values, are called domain. The values you get out of the equation, either f(x) or y are called range.