二元函数极限易犯的错误及其讨论

How discuss the easy-make mistakes in the limit of duality function

在二元函数极限中,学者易习惯性地受一元函数极限影响,忽略二元函数极限定义中的要求,常出现一些不符题意的做题方法。为此,作者特指出某些书中求二元函数极限易于出现的问题及应用海涅归结原则如何求解。

In the limit of duality function, learners are affected easily by the limit of unitary function, on the contrary, neglect the requirement of the definition of the limint of duality function, if like that, it is easy for the learners to solve the problem wrongly. So,the author points out some shortcomings on solving the limit of duality function and how to solve the problem by means of the ending principle.