A . dx+dy
B . dx-dy
C . dx+2dy
D . dx-2dy
[单选题]已知函数的全微分df(x,y)=(3x2+4xy-y2+1)dx+(2x2-2xy+3y2-1)dy,则f(x,y)等于( ).A.B.C.D.
[单选题]已知函数的全微分df(x,y)=(3x2+4xy-y2+1)dx+(2x2-2xy+3y2-1)dy,则f(x,y)等于( ).A.B.C.D.
[单选题]已知函数的全微分df(x,y)=(3x2+4xy-y2+1)dx+(2x2-2xy+3y2-1)dy,则f(x,y)等于( ).A.B.C.D.
[单选题]设方程x2+y2+z2=4z确定可微函数z=z(x,y),则全微分dz等于( )。A.B.C.D.
[单选题]设方程x2+y2+z2=4z确定可微函数z=z(x,y),则全微分dz等于( )。A.B.C.D.
[单选题]设方程x2+y2+z2=4z确定可微函数z=z(x,y),则全微分dz等于( )。A.B.C.D.
[单选题]设方程x2+y2+z2=4z确定可微函数z=z(x,y),则全微分dz等于( )。A.B.C.D.
[单选题]设方程x2+y2+z2=4z确定可微函数z=z(x,y),则全微分dz等于( )。A.B.C.D.
[单选题]设方程x2+y2+z2=4z确定可微函数z=z(x,y),则全微分dz等于( )。A.B.C.D.
[单选题]设方程x2+y2+z2=4z确定可微函数z=z(x,y),则全微分dz等于( )。A.B.C.D.