论文部分内容阅读
教材在介绍充要条件时,有一个问题没有交待:除充分条件和必要条件外,我们平常所说的条件是什么条件? 如:求证方程ax~2+bx+c=0(a
In the introduction of sufficient and necessary conditions in the textbooks, there is a question that is not answered: What conditions do we usually speak of, besides sufficient conditions and necessary conditions? For example, the verification equation ax~2+bx+c=0 (a