论文部分内容阅读
一、原题再现(2014浙江五校联考理科第17题)已知椭圆x2/a2+y2/b2=1(a>b>0)的右焦点为F,过F作斜率为b/a的直线与椭圆交于A,B两点,若|FB|≥2|FA|,则椭圆的离心率e的取值范围是.解析考后,学生反映此题很难,尤其是计算量太大.在进行试卷讲评时我围绕焦点弦进行了一些探究,得到了椭圆焦点弦的这一性质:
First, the original title reappearance (2014 Zhejiang five college entrance examination science subjects No. 17) Known elliptic x2 / a2 + y2 / b2 = 1 (a> b> 0) right focus F, F for the slope of b / a The intersection of the straight line and the ellipse intersects at A and B. If | FB | ≥2 | FA |, then the range of the elliptic eccentricity e is 0. After analyzing the test, it is very difficult for the students to reflect this question, especially the calculation too Large. In the papers commenting on the focus I made some exploration of the string, obtained the nature of the oval focus chord: