论文部分内容阅读
2011年高考全国大纲卷理科第21题,2005高考湖北卷理科第21题(也即文科第22题)2002年高考江苏、广东卷第20题都是关于二次线上四点共圆的问题(见文献[1],[2]).笔者曾2005年的这道高考题得出了二次曲线上四点共的一个简洁充要条件(其证明也很简洁但有技巧):若两条直线li:y-y0=ki(x-x0)(i=1,2与二次曲线Γ:ax2+by2+cx+dy+e=0(a≠b有四个交点,则这四个交点共圆的充要条件是k1+
2011 National College Entrance Examination Volume 21 subjects, 2005 Hubei University Science Entrance Examination Section 21 (that is, the first 22 subjects) 2002 college entrance examination in Jiangsu, Guangdong Volume 20 questions are on the secondary line of four o’clock (See references [1], [2]). The author had this 2005 college entrance examination test results on the quadratic curve of a total of four points of a concise and necessary conditions (the proof is also very simple but skillful): If the two The straight line li: y-y0 = ki (x-x0) (i = 1,2 and the quadratic curve Γ: ax2 + by2 + cx + dy + e = 0 (a ≠ b has four intersection points, The necessary and sufficient condition for intersection point is k1 +