平面直角坐标系架起数形结合的桥梁,使得我们可以用代数的方法研究几何问题,也可以用几何的方法研究代数问题.因此许多以直角坐标系为背景的试题成为考试的热点,其中有一类涉及“抛物线或圆与坐标轴交点(公共点)个数”产生的多解题成为考试命题的亮点,值得关注.一、圆与坐标轴恰有三个公共点产生的多解题 Plane Cartesian coordinate system raises the number of the bridge, so that we can use the algebraic method to study the geometry problem, also can use the geometric method to study the algebra problem.Therefore, many of the questions in the Cartesian coordinate system as the background to become the examination hotspot, including one Class involving “parabola or circle and the intersection of the axis and the axis (the number of common points) ” The multi-problem solution to become the highlight of the examination proposition, it is worth attention. First, the circle and the axis just three common points of multi-solution