Basic Analysis I — Real Analysis · Problem 1.2.8

Real Numbers — Jiri Lebl

Mathematics — Real Analysis · density-of-irrationals

Problem

Show that for every pair of real numbers xx and yy such that x<yx < y, there exists an irrational number ss such that x<s<yx < s < y. Hint: Apply the density of Q\mathbb{Q} to x2\dfrac{x}{\sqrt{2}} and y2\dfrac{y}{\sqrt{2}}.

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