∵cos(θ-π/6)＝3/5,θ∈(π/6,2π/3),求 ∴θ-π/6∈(0,π/2) sin(θ-π/6)=4/5 ∴sinθ =sin[(θ-π/6)+π/6] =sin(θ-π/6)cosπ/6+cos(θ-π/6)sinπ/6 =4/5*√3/2+3/5*1/2 =(4√3+3)/10
