[-4, 10] You first draw a blank number line line this -------------------------------------------------------------- -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Since it has brackets [ ] on the ends and not parentheses( ), we draw two solid circles at -4 and 10, like this: ----------⚫----------------------------------------⚫--------- -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Then you shade the line between them: ----------⚫========================================⚫--------- -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 And that is the graph of the interval [-4,10]. --- A bracket next to an endpoint means that you include the endpoint. A parentheses next to an endpoint means you do not include the endpoint. -- Here are examples of other intervals: ----------⚪========================================⚫--------- -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 That is the graph of the interval (-4,10] --- ----------⚫========================================⚪--------- -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 That is the graph of the interval [-4,10) --- ----------⚪========================================⚪--------- -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 That is the graph of the interval (-4,10) If an endpoint is included, the interval is said to be CLOSED there. If an endpoint is not included, the interval is said to be OPEN there. Edwin