Difference between revisions of "Interval"

(Examples)
(Examples)
 
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* <math>[5, \infty)</math> means all real numbers greater than or equal to <math>5.</math>
 
* <math>[5, \infty)</math> means all real numbers greater than or equal to <math>5.</math>
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 +
* <math>[6,98]</math> means all real numbers between <math>6</math> and <math>98</math>, including <math>6</math> and <math>98.</math>
  
  
 
Use latex \infty for infinity symbol and use latex \cup for OR symbol.
 
Use latex \infty for infinity symbol and use latex \cup for OR symbol.

Latest revision as of 18:34, 5 January 2024

Definition

An interval is a continuous range of values, such as all of the real numbers between $-2$ and $0,$ 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 $-\infty$ and $\infty,$ by convention.

Examples

  • $(2,3)$ 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 $0.$
  • $[5, \infty)$ means all real numbers greater than or equal to $5.$
  • $[6,98]$ means all real numbers between $6$ and $98$, including $6$ and $98.$


Use latex \infty for infinity symbol and use latex \cup for OR symbol.