我们知道 ,要断定一个命题正确 ,必须经过严格的推证 ,而要否定一个命题 ,只需举出一个反例 .在数学中举反例 ,既是简明有力的否定方法 ,又是加深对概念和定理理解的重要手段 .举反例有助于发现问题、活跃思维、避免常犯、易犯有关错误 .高中阶段的概率内容 ,学生感到有趣 ,也 We know that to conclude that a proposition is correct must be rigorously deduced, and to deny a proposition it is only necessary to cite a counterexample. Giving a counterexample in mathematics is both a concise and powerful method of negation and a deeper understanding of concepts and theorems. Is an important means. Taking counterexamples will help you find problems, be active in thinking, avoid common mistakes, and be apt to make mistakes. The content of high school students is interesting because of the probability content.