多元函数的教学是高等数学教学中的一个难点。
According to unary function limit and multivariate function limit of mathematical Analysis, the validity of the index Vnew is proved in theory.并根据数学分析中一元函数和多元函数的极限的相关知识,在理论上证明了该指标的有效性。
In this paper we give a method of test, which makes use of the gradient, to verify the extreme value of multivariate function, and give some typical examples.本文给出了利用梯度判定多元函数极值的判别法,并提供了若干范例。