Difference between revisions of "Range"

 
(3 intermediate revisions by 2 users not shown)
Line 2: Line 2:
  
 
Thus, if we have <math>f: \mathbb{R} \to \mathbb{R}</math> given by <math>f(x) = x^2</math>, the range of <math>f</math> is the set of [[nonnegative]] [[real number]]s.
 
Thus, if we have <math>f: \mathbb{R} \to \mathbb{R}</math> given by <math>f(x) = x^2</math>, the range of <math>f</math> is the set of [[nonnegative]] [[real number]]s.
 
  
 
A function is a [[surjection]] exactly when the range is equal to the codomain.
 
A function is a [[surjection]] exactly when the range is equal to the codomain.
Line 8: Line 7:
 
== See also ==
 
== See also ==
 
* [[Set notation]]
 
* [[Set notation]]
* [[Table of Contents]]
 
  
 
[[Category:Definition]]
 
[[Category:Definition]]
 +
{{stub}}

Latest revision as of 19:15, 3 February 2016

Let $A$ and $B$ be any sets and let $f:A\to B$ be any function between them, so that $A$ is the domain of $f$ and $B$ is the codomain. Then $\{b\in B\mid \mathrm{there\ is\ some\ } a\in A\mathrm{\ such\ that\ } f(a)=b\}$ is called the range or image of $f$.

Thus, if we have $f: \mathbb{R} \to \mathbb{R}$ given by $f(x) = x^2$, the range of $f$ is the set of nonnegative real numbers.

A function is a surjection exactly when the range is equal to the codomain.

See also

This article is a stub. Help us out by expanding it.