Difference between revisions of "Interval"

Revision as of 22:14, 16 August 2013

An interval is a range of values. The most common uses of an interval are to specify the domain and range of a function.

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 $-\infty$ and $\infty,$ by convention.

$(2,3)$ means all real numbers between $2$ and $3,$ but not including $2$ or $3.$

$[-2,0)$ means all real numbers between $-2$ and $0,$ including $-2,$ but not including $0.$

@@ Line 11: / Line 11: @@
 If both endpoints are not included, then the interval is '''open.''' If both endpoints are included, then the interval is '''closed.'''
-''Note'': The symbols <math>(</math> and <math>)</math> are used with <math>-\infty</math> and <math>\infty,</math> by convention
+''Note'': The symbols <math>(</math> and <math>)</math> are used with <math>-\infty</math> and <math>\infty,</math> by convention.
 == Examples ==