关于x的函数f(x)=2sinxcosxcosΦ+(1-2sin^2x)sinΦ(-派
问题描述:
关于x的函数f(x)=2sinxcosxcosΦ+(1-2sin^2x)sinΦ(-派
答
f(x)=2sinxcosxcosΦ+(1-2sin^2x)sinΦ
=sin2xcosΦ+cos2xsinΦ
=sin(2x+Φ)
-1=
答
f(x)=2sinxcosxcosΦ+(1-2sin^2x)sinΦ
=sin2xcosΦ+cos2xsinΦ
=sin(2x+Φ)
-1=
若一条对称轴为x=π\6,则2×π\6+Φ=π/4+Kπ/2,K属于整数
Φ=Kπ/2-π/12,因为-π所以tan(Φ+π\3)=1或-1
答
f(x)=2sinxcosxcosΦ+(1-2sin^2x)sinΦ即: f(x) = sin2xcosΦ + cos2xsinΦ = sin(2x + Φ)可见f(x)的最小正周期为π 值域为[ -1 , 1 ]f(x) = sin(2x + Φ),可知(2x + Φ) =π /2 +kπ 是其对称...