∴
du |
dx |
?f |
?x |
?f |
?y |
dy |
dx |
?f |
?z |
dz |
dx |
又由exy-y=0,兩邊對x求導(dǎo)得:exy(y+x
dy |
dx |
dy |
dx |
∴
dy |
dx |
yexy |
1?xexy |
y2 |
1?xy |
由ez-xz=0,兩邊對x求導(dǎo)得:ez
dz |
dx |
dz |
dx |
∴
dz |
dx |
z |
ez?x |
z |
x(z?1) |
∴代入①得:
du |
dx |
?f |
?x |
y2 |
1?xy |
?f |
?y |
z |
x(z?) |
?f |
?z |
du |
dx |
du |
dx |
?f |
?x |
?f |
?y |
dy |
dx |
?f |
?z |
dz |
dx |
dy |
dx |
dy |
dx |
dy |
dx |
yexy |
1?xexy |
y2 |
1?xy |
dz |
dx |
dz |
dx |
dz |
dx |
z |
ez?x |
z |
x(z?1) |
du |
dx |
?f |
?x |
y2 |
1?xy |
?f |
?y |
z |
x(z?) |
?f |
?z |