Domain & Range
Notation
Domain and range are sometimes expressed as intervals. Use the open parentheses if the domain and range exclude the starting and ending values. Use square brackets [ ] if the domain and range include the starting and ending values.
Examples
1. (-3, 5) ? All numbers between -3 and 5, not including -3 and 5. ? ?3 < x < 5
2. [-3, 5] ? All numbers between -3 and 5, including -3 and 5. ? ?3 ? x ? 5
3. [-3, 5) ? All numbers between -3 and 5, including -3 but not 5. ? ?3 ? x < 5
4. (-?, 10]? All numbers less than or equal to 10. ? x ?10
5. (-?, 4) (4, ?) ? All numbers less than 4, and all numbers greater than 4. In other words, all numbers except 4. ? x ? 4