“解题的成功要靠正确思路的选择,要靠从可以接近它的方向去攻击堡垒”(美国数学家G·波利亚).解题过程就是不断地将未知转化为已知的过程.而“三角代换法”则是实现这种转化的重要手段之一.它的策略思想是:根据题目的结构特征,引进三角代换,利用三角知识解题的一种方法.用这种方法解某些数 “The success of the problem depends on the correct choice of thinking, to rely on the attack from the direction of approaching it to the stronghold” (American mathematician G · Polia) .The problem solving process is to continue to be unknown into known One of the important means to achieve this kind of transformation is the “Triangulation Substitution Method.” Its strategic thinking is: According to the structural characteristics of the subject, the introduction of trigonometry substitution, the use of triangular knowledge to solve a method. Use this method to solve some numbers