设中点为(m,n)则中点与定点连线的距离为根号(m-2)^2+(n+6)^2 弦心距为根号m^2+n^2 圆心宇定点的距离为根号40 则根据沟谷定理有 (m-2)^2+(n+6)^2 +m^2+n^2=40 2m^2-4m+2n^2+12n=0 化简的(m-1)^2+(n+3)^2=10 (轨迹也为园,圆心为(1,-3)