在研究几条线段长之和(或差)的最小值、最大值时,常常要把这些线段集中到一起,然后将其与某条长度固定的线段进行比较.把其中的部分特殊点进行恰当的轴对称变换,是实现这一目标的有效手段.一、为了在已知直线上寻找与同侧两点距离之和最小的点(异侧两点的话很好确定,连接两点与直线的交点即为所求),可通过轴对称变换,把 When studying the minimum and maximum values ​​of the sum (or difference) of several line segments, it is often necessary to bring the line segments together and then compare them with a fixed-length line segment. Some of the special points Axisymmetric transformation, is an effective means to achieve this goal.First, in order to find the nearest straight line and the ipsilateral two points and the smallest point (the other side of the two points is well established, the connection between two points and a straight line Intersection that is required), through axisymmetric transformation, the