混合偏导数相等的两个充分条件

Two Sufficient Conditions For Mixing Partial Differential Coefficient Equality

以二元函数为例讨论混合偏导数相等的条件,给出了两个比现行教材中更弱的混合偏导数相等的充分条件。

Using two dimensional function as an example the writer gives two sufficient conditions for mixing partial diffevential coefficient equality.