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Four points at large distance

Source: HMIC 2019 Problem 3

April 28, 2019
algebraHMIC

Problem Statement

Do there exist four points Pi=(xi,yi)R2 (1i4)P_i = (x_i, y_i) \in \mathbb{R}^2\ (1\leq i \leq 4) on the plane such that:
[*] for all i=1,2,3,4i = 1,2,3,4, the inequality xi4+yi4xi3+yi3x_i^4 + y_i^4 \le x_i^3+ y_i^3 holds, and [*] for all iji \neq j, the distance between PiP_i and PjP_j is greater than 11?
Pakawut Jiradilok