Prove that a is a cluster point of E if and only if the set (E intersection (a-r,a+r))\{a} is nonempty for each r > 0.(adsbygoogle = window.adsbygoogle || []).push({});

I have the forward implication done but the backwards implication is giving me some trouble. Could you explain it to me.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Advanced Calculus proof

Loading...

**Physics Forums | Science Articles, Homework Help, Discussion**