排序不等式(排序原理)是一个重要不等式,用它来证明某类对称不等式比较简单.首先我们来介绍一下排序原理,原理如下:设a_1≤a_2≤…≤a_n,b_1≤b_2≤…≤b_n为两组实数,c_1,c_2,…,c_n是b_1≤b_2≤…≤b_n的任一排列,则 Order inequality (sorting principle) is an important inequality, it is used to prove that a class of symmetric inequalities is relatively simple.First, let us introduce the sorting principle, the principle is as follows: Let a_1≤a_2≤ ... ≤a_n, b_1≤b_2≤ ... ≤b_n Two sets of real numbers, c_1, c_2, ..., c_n are any one of b_1≤b_2≤ ... ≤b_n, then