椭圆x^2/a^2+y^2/b^2=1,左焦点F1(-c,0),A(-a,0)B(0,b)为2个顶点,F1到直线AB的距离为b/根号7,
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椭圆x^2/a^2+y^2/b^2=1,左焦点F1(-c,0),A(-a,0)B(0,b)为2个顶点,F1到直线AB的距离为b/根号7,
椭圆x^2/a^2+y^2/b^2=1,左焦点F1(-c,0),A(-a,0)B(0,b)为2个顶点,F1到直线AB的距离为b/根号7,
椭圆x^2/a^2+y^2/b^2=1,左焦点F1(-c,0),A(-a,0)B(0,b)为2个顶点,F1到直线AB的距离为b/根号7,
解析:由题意椭圆的右准线方程可写为:x=a&#178;&#47;c由此可知点E(a&#178;&#47;cbf0)是右准线与x轴的交点在△AF1E中nrvzF1A&#47;&#47;F2B则|F2B|&#47;|F1A|=|EF2|&#47;|EF1|因为|F1A|=2|F2B|fjnr|EF2|=a&#178;&#47;c -c|EF1|=a&#178;&#47;c +c所以(a&#178;&#47;c -c)&#47;(a&#178;&#47;c +c)=1&#47;2即a&#178;&#47;c +c=2(a&#178;&#47;c -c)a&#178;&#47;c =3c则c&#178;&#47;a&#178;=1&#47;3所以椭圆的离心率为e=c&#47;a=√3&#47;3