已知函数f(x)=2根号2sinwxcos(wx+兀⼀4)(w>0)的最小正周期为兀 求W

2024-12-04 05:30:40
推荐回答(3个)
回答(1):

回答(2):

f(x)=2√2sinwxcos(wx+π/4)
=2√2sinwx(coswxcosπ/4-sinwxsinπ/4)
=2√2sinwx*√2/2(coswx-sinwx)
=2sinwxcoswx-2sin^2 wx
=sin2wx +cos2wx-1
=√2sin(2w+π/4) -1
∴T最小=2π/2w=π
w=1

回答(3):

f(x)=2√2sinωxcos(ωx+π/4)
=2√2sinωx(√2/2cosωx-√2/2sinωx)
=2sinωx(cosωx+sinωx)
=2sinωxcosωx+2sinωx
=sin2ωx-cos2ωx+1
=√2sin(2ωx-π/4)+1
因为T=2π/ω,所以2ω=2π/T=2,所以ω=1