对有向线段的定比分点坐标公式及其应用大家都很熟悉 ,而对该公式的向量形式及由此衍生出的系列性质和应用的认识则要逊色得多 .本文试对此作一探索 ,以期抛砖引玉 ,使对定比分点公式的理解更趋完善 .定理 1　设Ｐ1 、Ｐ2是直线ｌ上的两点 ,点Ｐ是ｌ上不同于Ｐ1 、Ｐ2 的任一点 We are all familiar with the formula and application of the fixed-spot coordinates of directed lines, and the vector form of the formula and the series of properties and applications derived from it are much less familiar. This article tries to explore this. , With a view to throwing bricks and jade, so that the understanding of the formula of the fixed point score is more perfect. Theorem 1 Let P1, P2 be two points on the line l, point P is any point on the l is different from P1, P2