摘要
一、试题原文1. For each integer n > 1, let p(n) denote the largest prime factor of n. Determine all triples x,y,z of distinct positive integers satisfying(i) x,y,z are in arithmetic progression and(ii) p(xyz)≤3.2. Let ABC be a triangle and let D be a point on AB such that 4AD = AB. The half - line l is drawn on the same side of AB as C, starting from D and making an angle of θwith DA where θ=∠ACB. If
