(sin²θ+4)/(cosθ+1)-2=0sin²θ+4-2cosθ-2=0-cos²θ+3-2cosθ=0(cosθ+3)(1-cosθ)=0cosθ+3=0(舍) cosθ=1 sinθ=0(cosθ+3)(sinθ+1)=(1+3)(0+1)=4
