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技巧1:常规性程序巧变化例1(2012年高考重庆理科卷第20题)如图1,设椭圆的中心为原点O,长轴在x轴上,上顶点为A,左、右焦点分别为F1,F2,线段OF1,OF2的中点分别为B1,B2,且△AB1B2是面积为4的直角三角形.(Ⅰ)求该椭圆的离心率和标准方程;(Ⅱ)过B1作直线l交椭圆于P,Q两点,使PB2⊥QB2,求直线l的方程.难度系数0.60分析本题的第(Ⅰ)小题可利用待定系数法结合图形特征求得椭圆的方程.第(Ⅱ)小题可设出
Tip 1: Conventional Procedures Excercise Example 1 (2012 college entrance examination in Chongqing Science Volume 20) Figure 1, set the center of the oval as the origin O, the long axis on the x-axis, the top vertex is A, left and right focus respectively Is F1, F2, the midpoints of the segments OF1 and OF2 are B1 and B2, respectively, and ΔAB1B2 is a right-angled triangle with an area of 4. (I) Determine the eccentricity and standard equation of the ellipse; The intersection of ellipse and P, Q two points, so PB2 ⊥ QB2, find the equation of the straight line l difficulty coefficient 0.60 Analysis of the title of the first part of the problem can be determined by the coefficient of law combined with the graphical characteristics of the ellipse equation. Quiz can be set out