x=sinθ+cosθy=sin³θ+cos³θx²=(sinθ+cosθ)²=sin²θ+cos²θ+2sinθcosθ=1+2sinθcosθsinθcosθ=(x²-1)/2y=sin³θ+cos³θ=(sinθ+cosθ)(sin²θ-sinθcosθ+cos²θ)=x[1-(x²-1)/2]=(3x-x³)/2x³-3x+2y=0
