(1)直线的方程可化为, 直线的斜率,······················································································ 2分 因为, 所以,当且仅当时等号成立. 所以,斜率的取值范围是.·································································· 5分 (2)不能.··········································································································· 6分 由(Ⅰ)知的方程为 ,其中. 圆的圆心为,半径. 圆心到直线的距离 .························································································· 9分 由,得,即.从而,若与圆相交,则圆截直线所得的弦所对的圆心角小于. 所以不能将圆分割成弧长的比值为的两段弧.············································· 12分 |