直线kx-y+1=0与圆x^2+y^2=4相交于A,B两点,O是坐标原点

2025-12-13 02:41:27
推荐回答(1个)
回答1:

设A(x1,y1),B(x2,y2),两点在圆上:
x1^2+y1^2=1
x2^2+y2^2=1
k=(y1-y2)/(x1-x2)
相减整理得:(x1+x2)+(y1+y2)k=0
设C为AB中点(x,y),由上得:
x+ky=0
kx-y+1=0
联立消去k,可解得其轨迹为:
x^2 +(y-1/2)^2=1/4