如何充分发挥向量这一重要数学工具的功能已是一线教师非常关注的课题.本文仅就如何利用向量来处理轨迹问题中的共线点举两例说明.例1如图1,已知△OBC的顶点O(0,0),B(2,0),点C在抛物线y=x2+2x+3上运动,M、N分别在OB、OC上且满足OM∶M B=1∶2,ON∶N C=1∶3,BN与CM交于点P.图1(1) How to make full use of the function of the vector, an important mathematical tool, is a subject of great concern to front-line teachers. This article only gives two examples of how collinear points are used to deal with trajectories with vectors. Example 1 Figure 1 Known △OBC The vertices O(0,0), B(2,0), point C move on the parabola y=x2+2x+3, M, N are on OB, OC and satisfy OM:MB=1:2, ON : NC=1:3, BN and CM intersect at point P. Figure 1(1)