For double limit of a binaryfunction, the existence of the limit and the methods to seek its solution are emphasis among our focus.
对于二元函数的二重极限,重点是极限的存在性及其求解方法。
2
The criterion extreme value of binaryfunction for first partial derivative is given by means of the mean value theorem. The two theorems are obtained.
以中值定理为工具,给出了利用一阶偏导数判定二元函数极值的方法。
3
A discussion of the relations between continuity, partial derivative, directional derivative and differentiability of binaryfunction is helpful for us to study binaryfunction.