2023 CMO Problems/Problem 2

Revision as of 03:42, 25 May 2024 by Anyu tsuruko (talk | contribs) (Created page with "Find the largest real number <math>C</math> such that for any positive integer <math>n</math> and any real numbers <math>x_1, x_2, \ldots, x_n</math>, the following inequality...")
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Find the largest real number $C$ such that for any positive integer $n$ and any real numbers $x_1, x_2, \ldots, x_n$, the following inequality holds: \[\sum_{i=1}^n \sum_{j=1}^n(n-|j-i|) x_i x_j \geq C \sum_{i=1}^n x_i^2\]

Solution 1

See also

2023 CMO(CHINA) (ProblemsResources)
Preceded by
First Problem
Followed by
Problem 2
1 2 3 4 5 6
All CMO(CHINA) Problems and Solutions