一道最值问题引起的思考

• 作 者: 杨凤莲
• 机 构: 青海省大通县第七中学,
• 出 处: 新课程学习(中)
• 发表日期: 2013年08期

在高三数学复习中经常会遇到这样一类题型,求一点到另外两点距离之差的最大值,和求一点到另外两点距离之和的最小值。笔者认为,要做好这道题需对这道题的意思进行深刻地体会之后再解答便易如反掌了。例:在直线l:3x-y-1=0上求一点P,使得:(1)P到A(4,1)和B(0,4)的距离之差最大。

In the senior high school mathematics review often encounter such a type of questions, find the distance to the other two points the difference between the maximum, and seek a little to the other two points and the minimum distance. In my opinion, to do a good job in this issue, we need to understand the meaning of this question and understand it afterwards. Example: Find a point P on the line l: 3x-y-1 = 0 such that: (1) The difference between P and A (4,1) and B (0,4) is the largest.