∵sin(π/2-2θ)=sin(π/2)*cos(2θ)-cos(π/2)*sin(2θ)=cos(2θ)=1-2*（sinθ）^2又∵cos(π+θ)=cosπ*cosθ-sinπ*sinθ=-cosθ∴原式子=√3sinθ+1-2*（sinθ）^2=1 ∴2*sin²θ-√3sinθ=0 ∴sinθ=0或√3...