x^2/16+y^2/9=1,A,B是椭圆上两点,A,B的垂直平分线与X轴交于p(x0,0),求x0的取值范围.
问题描述:
x^2/16+y^2/9=1,A,B是椭圆上两点,A,B的垂直平分线与X轴交于p(x0,0),求x0的取值范围.
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答
设A(x1,y1),B(x2,y2),设直线AB的中点为点D,点D的坐标为((x1+x2)/2,(y1+y2)/2),直线AB的斜率为,(y2-y1)/(x2-x1)直线DP的斜率为,k=-(x2-x1)/ (y2-y1)直线DP的方程为y-(y1+y2)/2=-[(x2-x1)/ (y2-y1)]*(x-(x1+x2)/2)0-...