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近几年来,因陆续在杂志中读到几篇有关平面向量应用的文章,觉得十分有必要谈谈自己的一个感受:专业成长需要阅读.现先将文[1]、[2]中共同提及的问题摘录如下.例1如图1所示,在平行四边形ABCD中,E是DC的中点,AE交肋于M,试用向量的方法证明:M是BD的一个三等分点.证明:设DM=λDB=λ(AB-AB),AM=AD+DM=(1-λ)AD+λAB.因为E为DC的中点,所以.
In recent years, one after another in the magazine read articles related to the application of plane vector, I feel it is very necessary to talk about one of their own feelings: professional growth needs to be read first paper [1], [2] Excerpts from the example are as follows: Example 1 As shown in Figure 1, in a parallelogram ABCD, E is the midpoint of DC, AE intersects at M, and the trial vector proves that M is a trisection of BD. : Let DM = λDB = λ (AB-AB), AM = AD + DM = (1-λ) AD + λAB. Since E is the midpoint of DC.