Determine the range of the following graph: 12
11
10
9
8
100
1
-12-11-10-9-8-7-6-574-3-2-4
1 2 3 4 5 6 7 8 9 10 11 12
-2
-3
- 4
-5
-6
-8
-9
-10
-11
-12

The range is the set of all y-values used on the graph.

So start by asking yourself, “How low does the graph go?” Then ask, “How high does it get?” Then “Does it connect up and get everywhere in between?”

How low: -9, but not all the way, since that’s an open circle.
How high: 5 and it looks like it gets there
Everything in between: Yup!

Range: (-9,5]

( on -9 because it’s not included.
] on the 5 because it is included.