我们把用运向量研究，求解有关数学问题的方法称之为向量法.向量法的特点是形数结合，运算有法可循.用向量法研究平面几何问题与求解往往显得明快、简洁和容易人手，它克服了几何综合论证中常常需要添置若干辅助线而显得不易捉摸的缺点，同时又因为向量公式不依赖于坐标系，故 We use the vector to study and solve the mathematical problem-solving method called vector method. The vector method is characterized by the combination of the number of forms, the operation can be followed. Using vector method to study the plane geometry problems and solutions often appear to be fast, concise and easy Manpower, it overcomes the shortcomings that the geometric synthesis argument often needs to purchase a number of auxiliary lines and appears elusive. At the same time, because the vector formula does not depend on the coordinate system,