设y=,则dy的值是:()
A . ['['exdsin2x
B . sin2xdsinx
C . dsin2x
D . dsinx
[单选题]设y=x-5,则dy=().A.-5dxB.-dxC.dxD.(x-l)dx
[单选题]设y=ln(cosx),则微分dy等于()。A . ['B . cotxdxC . -tanxdxD .
[单选题]设y=ln(cosx),则微分dy等于()。A.B.cotxdxC.-tanxdxD.
[单选题]设y=ln(cosx),则微分dy等于()。A.B.cotxdxC.-tanxdxD.
[单选题]设y=sin(x-2),则dy=().A.-cosxdxB.cosxdxC.-cos(x-2)dxD.cos(x-2)dx
[单选题]设y=f(t),t=φ(x)都可微,则dy=()。A . f'(t)dtB . φ'(x)dxC . f'(t)φ'(x)dtD . f'(t)dx
[单选题]设y=f(t),t=φ(x)都可微,则dy=()。A.f′(t)dtB.φ′(x)dxC.f′(t)φ′(x)dtD.f′(t)dx
[单选题]设y=f(t),t=φ(x)都可微,则dy=()。A.f′(t)dtB.φ′(x)dxC.f′(t)φ′(x)dtD.f′(t)dx
[问答题]设方程x=yy确定y是x的函数,则dy=-----------.
[问答题]设方程x=yy确定y是x的函数,则dy=-----------.