Posted by haifeng on 2023-03-29 13:07:13 last update 2023-03-29 13:07:13 | Answers (1) | 收藏
设 $w=f(x+y+z,xyz)$, $f$ 具有二阶连续偏导数, 求 $\frac{\partial^2 w}{\partial x\partial z}$.
