设函数 z=xy+xyz=xy+xy, 则 dz=
A、(y+1y)dx+(x−xy2)dy(y+1y)dx+(x−xy2)dy;
B、(x−1y2)dx+(x+1y)dy(x−1y2)dx+(x+1y)dy;
C、(y+1y)dx+(x+xy2)dy(y+1y)dx+(x−xy2)dy;
D、(y+xy2)dx+(y+1y)dy(y+xy2)dx+(y+1y)dy.
发布时间:2024-11-06 15:01:12
A、(y+1y)dx+(x−xy2)dy(y+1y)dx+(x−xy2)dy;
B、(x−1y2)dx+(x+1y)dy(x−1y2)dx+(x+1y)dy;
C、(y+1y)dx+(x+xy2)dy(y+1y)dx+(x−xy2)dy;
D、(y+xy2)dx+(y+1y)dy(y+xy2)dx+(y+1y)dy.