人教版(A)普通高中课程标准实验教科书高中《数学》(选修2-1)第49页习题A组第7题是:如图,圆O的半径为定长r,A是圆O内一定点,P是圆上任意一点,线段AP的垂直平分线l和半径OP相交于点Q,当点P在圆上运动时,点Q的轨迹是什么?为什么?一、问题的解答 (A) ordinary high school curriculum standard experimental textbook high school mathematics (elective 2-1) 第 49 页 Exercises A group Question 7 is: As shown in the figure, the radius of the circle O is a fixed length r, A is a circle O within A certain point, P is any point on the circle, the vertical bisector of the line segment AP intersects with the radius OP at point Q. When the point P moves on the circle, what is the trajectory of point Q? Why?