)sin(x+
)的最小正周期T=______________. 
)sin(x+)的最小正周期T=______________. 答案：
(理)π f(x)=sin(x+)sin(x+)=sin(x+
)cosx=(
sinx+
cosx)cosx=
sinxcosx+
cos2x=
sin2x+
(1+cos2x)
=
sin2x+
cos2x+
=
sin(2x+
)+
.故T=
=π.