解: ln(x-z)=lne^(xyz)
ln(x-z)=xyz
进行求导: (1/(x-z))*(1-偏z/偏x)=yz+xy(偏z/偏x)
yz(x-z)+(x-z)xy(偏z/偏x)=1-偏z/偏x
xyz-yzz+(xxy-xyz)(偏z/偏x)=1-偏z/偏x
1-xyz+yzz=(1+xxy-xyz)(偏z/偏x)
得 : 偏z/偏x = (1-xyz+yzz)/(1+xxy-xyz)
两侧对x求偏导得到
e^x -ye^z -xye^zdz/dx =0, dz/dx = (e^x-ye^x)/xye^z
对y求偏导
e^y -xe^z -xye^zdz/dy =0, dz/dy = (e^y-xe^z)/xye^z
dz = (dz/dx)dx +(dz/dy)dy
= (e^x-ye^x)/xye^z dx +(e^y-xe^z)/xye^z dy