极坐标与直角坐标的换算关系：x=ρcos(θ),y=ρsin(θ)圆心在A(1,π/4)在直角坐标中便是(cosπ/4,sinπ/4)=(√2/2,√2/2)半径为1的圆的方程为：(x-√2/2)²+(y-√2/2)²=1即(ρcosθ-√2/2)²+(ρs...