在《二次根式》一章中，由于概念和法则比较抽象，同学们在计算与化简中常易发生这样或那样的错误．其中主要原因是忽略了题目中的隐含条件以及乱用公式、定理、性质、定义等所造成．下面通过举例来分析常见的几种错误．一、忽略定义中的隐含条件有些数学概念的定义本身就隐含? In the chapter “Secondary Roots”, because the concepts and rules are relatively abstract, students are often prone to errors of one kind or another in calculation and reduction. The main reason is the neglect of the implied conditions in the title and the inconsistent use of formulas, theorems, properties, definitions, etc. The following examples are used to analyze common errors. I. Ignoring Implied Conditions in Definitions The definition of some mathematical concepts is implicit in itself.