把原题,,,你的答案,,,,.标准答案给出即可.
最起码 题目要清楚
我来给过程,,这么乱怎么看?
事实证明你错的.
F(x,y,z) = z^3-2xz+y = 0
z'x = -F'x/F'z =2z/ (3z^2-2x)
z''xx = 2[z'x (3z^2-2x) - z(6zz'x-2)]/(3z^2-2x)^2
= 2[-3z^2 z'x - 2xz'x + 2z]/(3z^2-2x)^2
= 2[-3z^2 2z - 2x 2z + 2z(3z^2-2x)]/(3z^2-2x)^3
= -16xz/(3z^2-2x)^3