设B(b,0),圆B的半径为r,方程(x - b)² + y² = r²过M:(b - 2)² = r² ,r =± (b - 2)AB² = (b - 0)² + (0 - 3)² = b² + 9 = (r + 1)² (1) r = b - 2b² + 9 = (...