Question

两圆c1:x^2+y^2+2x+2y -8=0,C2:x^2+y^2-2x+10y-24=0相交于两点A,B,求经过A,

Answer 1

x^2+y^2+2x+2y -8=0·······················a

x^2+y^2-2x+10y-24=0·····················b

a,b两式相减得：x=2y-4······················c

将c式代入a 化简得y^2-2y=0 y=0或y=2

所以相交的亮点坐标为A（-4,0）、B（0,2）

所以过两点最小面积的圆圆心坐标为（-2,1）,半径为AB/2=根号五

圆方程为：（x+2）^2+(y-1)^2=5