自从新编高中数学教材(试验本)在必修课第五章增加了向量内容后,解决中学数学的许多问题又多了一种思路.把向量用到解析几何中,可以使许多解析几何问题的求解思路清晰、目标明确,易于掌握.例1已知⊙O的方程是x2+y2=9,求过点A(1,2)所作的圆的弦的中点P的轨迹方程.解A(1,2),O(0,0 Since the new high school mathematics textbook (test book) added the vector content in the fifth chapter of the required course, solving many problems in middle school mathematics has added a new idea. Using the vector in analytic geometry can make many analytical geometric problems. The solution has clear thinking, clear goals and easy to grasp. Example 1 It is known that the equation of ⊙O is x2+y2=9. Find the trajectory equation of the midpoint P of the circle made by point A(1,2). Solution A ( 1,2), O(0,0