“声东击西”巧解题

• 作 者: 杨文金
• 机 构: 山东省枣庄市第二中学,
• 出 处: 语数外学习(初中版)
• 发表日期: 2006年11期
• 关键词: 数学问题 解题策略 异向 题设 证明方法 逆推法 逆向推理 平方关系 归谬 解题过程

有一些数学问题,直接正面求解,难度很大．如果从求解目标的反向(或异向)入手,表面上似是解决目标之反面,实质上是解决了目标本身,这是一种巧妙的解题策略,可谓“声东击西”．

There are some mathematical problems, and it is very difficult to solve it directly. If you start from the reverse (or the opposite direction) of the solution goal, it seems to be the reverse of the goal. It essentially solves the goal itself. This is a clever problem-solving strategy.