文[1]深入挖掘平面向量基本定理,竟得解题妙招——回路法,不禁令人拍手称赞.书中曾多次出现两条相交线段所成比例的问题,有时用回路法解,有时用向量形式的定比分点公式解,本文将总结归纳此类问题的四种处理方法,供大家参考.书中的一道例题给出了该类问题的一个基本构架.例1如图1,在△ABC中,AM=1/3AB,AN=1/4AC,BN和CM相交于点P,试用AB和AC表示向量AP.分析:两条线段BN和CM相交,形成了一 Text [1] dig deep into the basic theorem of plane vectors, actually solve the problem coup - Circuit Act, can not help but make people clap praise. There have been many times in the book the proportion of intersecting segments of the problem, sometimes loop solution, and sometimes This paper will summarize the four kinds of processing methods of such problems for your reference.An example in the book gives a basic framework of such problems.Example 1 As shown in Figure 1, △ ABC, AM = 1 / 3AB, AN = 1 / 4AC, BN and CM intersect at point P, try AB and AC that vector AP. Analysis: The two line segments BN and CM intersect, forming a