Finite subset of a metric space

[rjw5002]

Homework Statement

Let X be an infinite set. For p,q \in X define:
d(p,q) = {1 if p \neq q; 0 if p = q
Suppose E is a finite subset of X, find all limit points of E.

Homework Equations

definition: a point p is a limit point of E if every neighborhood of p contains a point q \neq p s.t. q\inE

The Attempt at a Solution

My thoughts were that there are no limit points for any subset of X because for any point p, B(p, 1/n) is empty, \foralln\inN. Therefore, for any point p, there exists at least one neighborhood that contains no points q \in E.

I feel that this is true, but have I made any incorrect assumptions??
Thanks a lot for any feedback.

 

[morphism]

B(p,1/n) isn't empty for all n. For instance p is always in B(p,1/n), and if n=1, then B(p,1/n) is in fact all of X.

You definitely have the right idea, but you have to be a bit more careful.

 

[HallsofIvy]

remember that you have the additional rquirement that q\ne p. I think that is what you meant to say. For all n, B(p, 1/n) contains p, but for some n, B(p, 1/n) does not include any other point of the set.

 

[rjw5002]

Right, ok. I can fix that detail. Thanks a lot guys.

 

[nehakapoor]

i need the proof for every finite set is a closed set in a metric space ..
and finite set in a metric space in compact as soon as possible../.

 

[micromass]

i need the proof for every finite set is a closed set in a metric space ..
and finite set in a metric space in compact as soon as possible../.

You will need to make a new topic for this. And it would also be nice to see your attempt...