任何一个轨迹问题 ,不论动点多少 ,总可以分为二大类 ,即主动点 (在一定条件下可以相对自由运动的点 )与从动点 (随主动点运动而运动的点 ) .多动点轨迹问题的本质是 ,由主动点的运动规律探求从动点的轨迹 .一般地 ,在多动点轨迹问题中 ,主动点往往不止一个 ,这就使从动点与主 Any trajectory problem, irrespective of the number of moving points, can be divided into two major categories: active points (points that can move relatively freely under certain conditions) and follower points (points that move with active points). The essence of the point trajectory problem is that the trajectory of the driven point is explored by the motion law of the active point. Generally speaking, in the trajectory of the multi-point trajectory, there are often more than one active point, which makes the driven point and the main point.