圆锥曲线中的最值与范围问题是高考的考查热点,往往以圆锥曲线(包括圆)与直线为载体,结合函数、不等式及导数等知识,综合考查解题能力.求解这类问题的基本方法有几何特征法和代数法.几何特征法几何特征法即利用圆锥曲线的几何特征蕴含的条件,如抛物线上任意一点到焦点的距离等于其到准线的距离、过椭圆焦点的所有弦中通径最短等,构造相应的函数或不等式求解. The conic curve of the most value and scope of the problem is the entrance examination of hot spots, often conical (including the circle) and the line as the carrier, combined with knowledge of functions, inequalities and derivatives, a comprehensive examination of problem solving ability to solve such problems, the basic method There are geometric features and algebraic method Geometrical feature method Geometrical feature method is the use of geometric conformational features implied conditions, such as the distance from any point on the parabola to the focal point is equal to its distance from the quasi-elliptical, The shortest path, etc., construct the corresponding function or inequality solution.