In one of my old notes, I was reviewing this proof. It started with:(adsbygoogle = window.adsbygoogle || []).push({});

Consider [itex] S = \{ x \in \mathbb{R} \ | \ x^2 = 2, \ x > 0\} [/itex], then S is not empty because [itex]1 \in S[/itex]

Why is 1 in the set?

Thanks.

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# X^2 = 2 has solution in ℝ

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