Relation
Return to Glossary.
Formal Definition
A relation between sets $A$ and $B$ is a subset $\Re$ of $A \times B$.We read $(a,b)\in \Re$ as "$a$ is related to $b$" and write $a\Re b$.
Informal Definition
Replace this text with an informal definition.
Example(s)
The graph of the function $f$ where $f(x)=x$3 for all $x\in \Re$,is the subset $\{(x,x^3)|x\in \mathbb{R}\}$ of $\mathbb{R}\times\mathbb{R}$.Thus it is a relation on $\mathbb{R}$.
Non-example(s)
The graph of the function $f$ where $f(x)=x$2 for all $x\in \Re$,is the subset $\{(x,x^2)|x\in \mathbb{R}\}$ of $\mathbb{R}\times\mathbb{R}^+$.Thus it is not a relation on $\mathbb{R}$ because it doesn't graph the $\mathbb{R}^-$.
Additional Comments
Add any other comments you have about the term here.