Interval

Definition

An interval is a continuous range of values, such as all of the real numbers between and inclusive. The most common uses of an interval are to specify the domain and range of a function.

Symbols

If an interval has either or in it, the values at the end are NOT included in the interval.

If an interval has either or in it, the values at the end ARE included.

If both endpoints are not included, then the interval is open. If both endpoints are included, then the interval is closed.

Note: The symbols and are used with and by convention.

Examples

• means all real numbers between and but not including or

• means all real numbers between and including but not including

• means all real numbers greater than or equal to

Use latex \infty for infinity symbol.