试题(2014届徐州市高三第一次质量检测第18题)已知△ABC的三个顶点A(-1,0),B(1,0),C(3,2),其外接圆为⊙H.(1)若直线l过点C,且被⊙H截得的弦长为2,求直线l的方程;(2)对于线段BH上的任意一点P,若在以C为圆心的圆上都存在不同的两点M、N,使得点M是线段PN的中点,求⊙C的半径r的取值范围.试题问(2)是直线与圆相交的问题,然 Test questions (18th session of the first quality test of Grade 3 in 2014, Xuzhou) We know the three vertices A (-1,0), B (1,0) and C (3,2) of △ ABC, whose circumcircle is (1) If the line l crosses point C and the chord length cut by ⊙H is 2, find the equation of line l; (2) For any point P on line BH, There are two different points on the circle M, N, so that the point M is the midpoint of the line segment PN, find the radius r of ⊙C range. Question (2) is a straight line and the problem of intersection,