一、问题的提出充要条件的应用具有很大的广泛性,在高中数学教学中要时时渗透这种知识,在高考中,对简易逻辑的考查虽然仅是一道选择题或填空题,通常都是给出一个条件,问另一个条件是它的什么条件.然而,在教学中,如果仅仅停留在去判别到底是充分、必要或充要条件,笔者认为是远远不够的.简易逻辑在高中数学中占有极其重要的地位,作为一名中学数学教师,更应该用严密的逻辑思维 First, the question of the application of necessary and sufficient conditions has a wide range, in high school mathematics teaching from time to time to infiltrate this knowledge, in the college entrance examination, although the simple logic of the examination is only a multiple choice or fill in the blank, usually It is to give a condition, and ask what other condition is its condition. However, in teaching, if we just stop to discriminate whether it is sufficient, necessary or sufficient condition, I think it is not enough. Simple logic in high school Mathematics plays an extremely important role. As a middle school mathematics teacher, it should use strict logical thinking.