ρ=cosθ化成直角坐标系方程：(x-0.5)^2+y^2=0.25圆心（0.5,0）r=0.5
ρ=sinθ化成直角坐标系方程：(y-0.5)^2+x^2=0.25圆心（0,0.5）r=0.5