已知两圆x+y-2x+10y-24=0和x+y+2x+2y-8=0.求公共弦的长度
问题描述：
已知两圆x+y-2x+10y-24=0和x+y+2x+2y-8=0.求公共弦的长度
答
x'表根号x!1).(x-1)^2+(y+5)^2=50=50.A(-1,-5).(x+1)^2+(y+1)^2=10,B(-1,-1).|AB|^2=(1+2)^2+(-5+1)^2=20,|AB|=2'5'.2).圆交C、D,AB、CD交于E.CD丄AB,AE=x,BE=2'5'-x.RtACE,CE^2=AC^2-AE^2=50-x^2,BCE中,CE^2=10-(2'5'-x)^2.10-(2'5'-x)^2=50-x^2.4'5'x=60,x=3'5'.CE='5',CD=2CE=2'5'.