Make your own free website on
Home | Function | Domain & Range | Represent Date Using Function Models | Function Notation
Relations & Functions 101
Domain & Range

Domain: the set of values of the independent variable (X VALUES)
Range: the set of values of the dependent variables (Y VALUES)

To figure out Domain and range you must take the two ends of the segment and find the numbers that they represent on either the "x" or "y" axis.  You always have two numbers in the answer, unless you are using specific points. Then you must list all the points included. We have given some test questions to help you understand this concept.  Good Luck!

Now that you know what each means, you should know that we indicate domain and range by using different types of brackets..
(   )   -> NOT INCLUDING --> if on the graph has an open circle at the end it means that at that end there is an NOT INCLUDING bracket ex: [0, 28)
**IMPORANT RULE** --> when dealing with infinity it is automatically a NOT INCLUDING bracket.
[   ]   -> INCLUDING means that the the whole line is included ex: [0,29]
{  }    -> SPECIFIC POINTS is when there are specific points on the graph and in that case you must list ALL the numbers and place them inside these brackets. {2,4,6,8}

Okay, well it is time to see if you know how to figure this out! ... What is the domain and range for the following graphs?

Graph #1

Graph #2

Graph #3

An example of Specific points


Graph #1- Domain: [14.5,-infinity), Range: [0, infinity)
Graph #2- Domain: [0,15], Range: [100,200]
Graph #3- Domain: [-10, 17], Range: [-2,10]
Graph #4- Domain: {1,2,3}, Range: {1,2,3}
Graph #5- Domain: (2,20], Range: [0, 5)

Super Duper Math YAYY!