问题
填空题
函数f(x)=(sinx+cosx)cosx(x∈R)的最小正周期为______.
答案
函数f(x)=(sinx+cosx)cosx
=sinxcosx+cos2x
=
sin2x+1 2
(cos2x+1)1 2
=
(sin2x+cos2x)+1 2 1 2
=
sin(2x+2 2
)+π 4
,1 2
∵ω=2,∴T=
=π.2π 2
故答案为:π
函数f(x)=(sinx+cosx)cosx(x∈R)的最小正周期为______.
函数f(x)=(sinx+cosx)cosx
=sinxcosx+cos2x
=
sin2x+1 2
(cos2x+1)1 2
=
(sin2x+cos2x)+1 2 1 2
=
sin(2x+2 2
)+π 4
,1 2
∵ω=2,∴T=
=π.2π 2
故答案为:π