Let X=(x,y)inR^2:xy=1 and Y=(x,y)inR^2:x+y=1. Then:

(C) Y is compact, but X is not compact

Q51Section II (Mathematics)51 of 190

An unbounded hyperbola pair versus the compact $\ell^1$ -unit circle

Let $X=\{(x,y)\in\mathbb{R}^2:|x||y|=1\}$ and $Y=\{(x,y)\in\mathbb{R}^2:|x|+|y|=1\}$ . Then:

Pick an option to check your answer.

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