Let $X$ be a normed space. I want to prove that for any proper linear subspace $M$, there exists a point $x$ with $||x||=1$ such that $inf\{||x-y||:y\in M\}>1-\epsilon$ for arbitrary epsilon. Could anyone show me how to do this?
Proper Linear Subspaces
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functional-analysis
normed-spaces
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0Sorry, that was a typo. I meant greater than not less than. – 2012-11-12
1 Answers
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This is well known Riesz lemma. For the proof see this notes.