x-1/2)^2+(y+1)^2=5/4 圆心A(1/2,-1),过A作直线m⊥L:x－y＋1＝0.(1) m斜率-1,方程y+1=-1(x-1/2),x+y+1/2=0.(2) 由(1),(2)得m,l交点O(-3/4,1/4)为AA’中点 对称的圆心A’(x1,y1):(1/2+x1)/2=-3/4,x1=-2 (-1+y1)/2=1/4...