- #1
Ocifer
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Homework Statement
Let A,B be two disjoint, non-empty, compact subsets of a metric space (X,d).
Show that there exists some r>0 such that d(a,b) > r for all a in A, b in B.
Hint provided was: Assume the opposite, consider a sequence argument.
Homework Equations
N/A
The Attempt at a Solution
I've tried a few different characterizations of compactness, but neither one has led me anywhere particularly useful. I'm missing something such that the teacher's hint isn't helping me much.
If I assume the opposite,
Assume that for all r>0, there exists some pair (a,b) such that d(a,b) <= r
I sense that I am supposed to reach a contradiction regarding the property that any sequence in a compact A or B should have a convergent subsequence. But how do I show that I would reach such a contradiction. Can anyone give me a push in the right direction?