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Hi there, I have a set similar to this [tex]\{(x,y)\in{\mathbb{R}^2}:x^2+y^2\neq{k^2},k\in{\mathbb{Z}\}[/tex] (its the same kind, but with elipses).

And I don't know if it is convex or not. If I make the "line proof", then I should say no. What you say?

Bye there, and thanks.

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# Homework Help: Topology: is this a convex set?

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