(1)∵y=(1-
)(1+
x
)=1
x
-1
x
=x?
x
?x1 2
,1 2
∴y′=(x-
)′-(x1 2
)′=-1 2
x-1 2
-3 2
x-1 2
.1 2
(2)y′=(
)′=lnx x
=(lnx)′x?x′lnx x2
?x?lnx,x2)=+f(1 x
.1?lnx x2
(3)y′=(
)′=sinx cosx
(sinx)′cosx?sinx(cosx)′ cos2x
=
=cosxcosx?sinx(?sinx) cos2x
.1 cos2x
(4)y′=(xe1-cosx)′=e1-cosx+x(e1-cosx)′
=e1-cosx+x[e1-cosx?(1-cosx)′]
=e1-cosx+xe1-cosx?sinx
=(1+xsinx)e1-cosx.