若p(2,-1)为圆(x-1)²+y²=25的弦AB的中点,AB方程为_数学解答

若p(2,-1)为圆(x-1)²+y²=25的弦AB的中点,AB方程为

人气：207 ℃　时间：2020-05-09 02:49:08

解答

xA+xB=2xP=2*2=4,yA+yB=2yP=-2k(AB)=(yA-yB)/(xA-xB)=(y+1)/(x-2)[(xA-1)^2+(yA)^2]-[(xB-1)^2+(yB)^2]=1-1(xA+xB-2)*(xA-xB)+(yA+yB)*(yA-yB)=04-2+(-2)*(yA-yB)/(xA-xB)=01-(y+1)/(x-2)=0AB:x-y-3=0