Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2023-part-01 — 191 problems (EN–VI) Question 169

Math Olympiad Vault · MathNet 2023-part-01 — 191 problems (EN–VI)

Question 169

Does there exist an irrational number $x$ such that there are at most finitely many positive integers $n$ satisfying
$$
\{kx\} \geq \frac{1}{n+1}
$$
for every $k \in \{1, \dots, n\}$?

Note: Here, for a positive real number $y$, $\{y\}$ denotes the fractional part of $y$.