近几年来,数量积的问题在高考小题中出现的频率较高,甚至于出现在解答题中,而且常考常新,同时它又是考纲“C”级要求内容,我们应予以足够的重视。本文结合几个典型例题谈谈如何求平面向量的数量积,希望对读者有帮助。一、利用“定义”求平面向量的数量积 In recent years, the number of product problems in the college entrance examination in the small problems appear higher frequency, and even appear in the answer questions, and often test new, and it is the test syllabus “C ” level requirements, we should be Pay enough attention. In this paper, several typical examples to talk about how to find the number of planar vector product, I hope to help readers. First, the use of “definition ” to find the number of plane vector product