PlanetMath (more info)
 Math for the people, by the people.
Encyclopedia | Requests | Forums | Docs | Wiki | Random | RSS  
Login
create new user
name:
pass:
forget your password?
Main Menu
Owner confidence rating: High Entry average rating: No information on entry rating
bounded (Definition)

Let $ X$ be a subset of $ \mathbb{R}$. We say that $ X$ is bounded when there exists a real number $ M$ such that $ \vert x\vert<M$ for all $ x\in X$. When $ X$ is an interval, we speak of a bounded interval.

This can be generalized first to $ \mathbb{R}^n$. We say that $ X\subseteq \mathbb{R}^n$ is bounded if there is a real number $ M$ such that $ \Vert x\Vert<M$ for all $ x\in X$ and $ \Vert\cdot\Vert$ is the Euclidean distance between $ x$ and $ y$.

This condition is equivalent to the statement: There is a real number $ T$ such that $ \Vert x-y\Vert<T$ for all $ x,y\in X$.

A further generalization to any metric space $ V$ says that $ X\subseteq V$ is bounded when there is a real number $ M$ such that $ d(x,y)<M$ for all $ x,y\in X$, where $ d$ is the metric on $ V$.



"bounded" is owned by yark. [ full author list (3) | owner history (3) ]
(view preamble)

View style:

See Also: Euclidean distance, metric space

Also defines:  bounded interval
Log in to rate this entry.
(view current ratings)

Cross-references: metric, metric space, Euclidean distance, interval, real number, subset
There are 42 references to this entry.

This is version 8 of bounded, born on 2003-10-15, modified 2006-05-20.
Object id is 4826, canonical name is BoundedInterval.
Accessed 6930 times total.

Classification:
AMS MSC54E35 (General topology :: Spaces with richer structures :: Metric spaces, metrizability)

Pending Errata and Addenda
None.
[ View all 2 ]
Discussion
Style: Expand: Order:
forum policy

No messages.

Interact
post | correct | update request | add derivation | add example | add (any)