已知圆O的方程为x2+y2=10,求过点A(2,1)的弦的中点p的轨迹,谢谢!
问题描述:
已知圆O的方程为x2+y2=10,求过点A(2,1)的弦的中点p的轨迹,谢谢!
答
弦BCP(x,y)xB+xC=2x,yB+yC=2y(xB)^2+(yB)^2=10.(1)(xC)^2+(yC)^2=10.(2)(1)-(2):(xB+xC)*(xB-xC)+(yB+yC)*(yB-yC)=0k(BC)=(yB-yC)/(xB-xC)=-(xB+xC)/(yB+yC)=(yP-yA)/(xP-xA)-2x/(2y)=(y-1)/(x-2)中点p的轨迹圆:(x-1...