直角坐标系的创建,为代数和几何架起了一座桥梁,使得几何问题得以转化为代数问题来解决,为解决几何问题开辟了新思路.而极坐标系,在将几何研究对象转化为代数研究对象的同时,保留了几何中重要的元素——长度和角度.因此,在圆锥曲线中,我们可应用极坐标巧解问题. The establishment of Cartesian coordinate system bridges the algebra and geometry, which makes it possible to convert geometric problems into algebraic problems and opens up new ideas for solving geometric problems. However, in the polar coordinate system, the object of geometric research is transformed into algebraic research In the meantime, we keep the important elements in the geometry - the length and the angle, so that in the conic we can apply the polar coordinate solution.