Question

若3cosα-3√3sinα=6sin(α+φ),φ属于(0,2π),则φ=?

Answer 1

3cosα-3√3sinα=6sin(α+φ),

6(1/2cosα-√3/2sinα)=6sin(α+φ)

sin(π/6-α)=sin(α+φ)

sin[π-(π/6-α)]=sin(α+φ)

sin(5π/6+α)=sin(α+φ)

α+φ=5π/6+α

则：φ=5π/6