问题描述: 过点M(1,1)的直线与椭圆x^2/16+y^2/4=1交于P1,P2两点,求弦P1,P2的中点的轨迹方程 1个回答 分类:数学 2014-11-03 问题解答: 我来补答 设P1(x1,y1)P2(x2,y2)中点为(x,y)根据题意即x1+x2=2x,y1+y2=2y且(y1-y2)/(x1-x2)=(y-1)/(x-1)椭圆方程x²/16+y²/4=1即x²+4y²=16代入P1P2坐标x1²+4y1²=1x2²+4y2²=1两式相减x1²-x2²+4(y1²-y2²)=0(x1+x2)(x1-x2)+4(y1+y2)(y1-y2)=0(x1+x2)+4(y1+y2)(y1-y2)/(x1-x2)=02x+8y*(y-1)/(x-1)=0x²-x+4(y²-y)=0(x-1/2)²+4(y-1/2)²=5/4即为所求轨迹 展开全文阅读