(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Let X = R2 with the Euclidean metric and let S = {(x1, x2) : x1^2+x2^2 <1}.Prove that Closure of S ={(x1,x2):x1^2+x2^2<= 1} and that the Boundary of S= { (x1, x2) : x1^2 +x2 ^2=1 } .

2. Relevant equations

3. The attempt at a solution

I was able to prove all my theorems but I don't know how to prove this concrete example. All my theorems just talked about one point in the closure or boundary. I can clearly see from a picture that these are the answers but how do I prove it without a picture?

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# Homework Help: How do I prove the closure and the boundary of a concrete example?

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