若3sinx-根3cosx=2根3sin(x-ρ)ρ∈(-π,π)则ρ=

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若3sinx-根3cosx=2根3sin(x-ρ)ρ∈(-π,π)则ρ=

若3sinx-根3cosx=2根3sin(x-ρ)ρ∈(-π,π)则ρ=
若3sinx-根3cosx=2根3sin(x-ρ)ρ∈(-π,π)则ρ=

若3sinx-根3cosx=2根3sin(x-ρ)ρ∈(-π,π)则ρ=
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

3sinx-√3cosx=2√3sin(x+ψ)
2√3(√3/2 sinx-1/2 cosx)=2√3sin(x+ψ)
2√3(cos30×sinx - sin30×cosx)=2√3sin(x+ψ)
2√3 sin(x -30)=2√3 sin(x+ψ)
所以ψ= -30= -π/6(ψ∈(-π,π