MathDB
Distance of points

Source:

September 9, 2010
geometrygeometric inequalityoptimizationminimizationmaximizationIMO Shortlistpoint set

Problem Statement

Let P1,P2,,PnP_1, P_2, \dots , P_n be distinct points of the plane, n2n \geq 2. Prove that max1i<jnPiPj>32(n1)min1i<jnPiPj \max_{1\leq i<j\leq n} P_iP_j > \frac{\sqrt 3}{2}(\sqrt n -1) \min_{1\leq i<j\leq n} P_iP_j