Question

设全集I=R,已知集合M=﹛x|﹙x＋3﹚²≤0﹜,N=﹛x|x²＋x－6=0﹜

Answer 1

（1）M = ｛x丨（x + 3）² ≤ 0｝= ｛- 3｝

N = ｛x 丨x ² + x - 6 = 0｝= ｛- 3,2｝

∴ CI M = ｛x 丨x ≠ - 3｝

(CI M) ∩ N = ｛2｝

（2）A = (CI M) ∩ N = ｛2｝

∵ B ∪ A = A

∴① 当 B 为空集时,则：a - 1 > 5 - a

2 a > 6

a > 3

② 当 B 不为空集时,则：

a - 1 = 5 - a = 2

∴ a = 3

综上,a的取值范围是 a ≥ 3