若3sinx-根3cosx=2根3sin(x-ρ)ρ∈（-π,π）则ρ=
问题描述：
若3sinx-根3cosx=2根3sin(x-ρ)ρ∈（-π,π）则ρ=
答
3sinx-√3cosx
=2√3(sinx*√3/2-cosx*1/2)
=2√3(sinxcosπ/6-cosxsinπ/6)
=2√3sin(x-π/6)
=2√3sin(x-ρ)
所以ρ=π/6