(x-3)^2+(y-π)^2=9
所以x^2-6x+9+y^2-2πy+π^2=9
x^2+y^2-6x-2πy+π^2=0
由x^2+y^2=ρ^2,x=ρcosθ,y=ρsinθ得
ρ^2-6ρcosθ-2πρsinθ+π^2=0
即极坐标方程是ρ^2-6ρcosθ-2πρsinθ+π^2=0