sinαcos60度-cosαsin60度=1/2即sin(α-π/3)=1/2
α∈(0,2π),α-π/3∈(-π/3,5π/3),而sin(α-π/3)=1/2>0
所以α-π/3∈(0,π),因为sin(α-π/3)=1/2,
所以α-π/3=π/6或5π/6 α=π/2或7π/6