Đề bài

Cho hai tập hợp: \(A = [0;3]\), \(B = (2; + \infty )\). Xác định \(A \cap B,A \cup B,\)\(A\,{\rm{\backslash }}\,B,B\,{\rm{\backslash }}\,A,\mathbb{R}\,{\rm{\backslash }}\,B.\)

Lời giải chi tiết

+) \(A \cap B = [0;3] \cap (2; + \infty ) = (2;3]\)

+) \(A \cup B = [0;3] \cup (2; + \infty ) = [0; + \infty )\)

+) \(A\,{\rm{\backslash }}\,B = [0;3]\,{\rm{\backslash }}\,(2; + \infty ) = [0;2]\)

+) \(B\,{\rm{\backslash }}\,A = (2; + \infty )\,{\rm{\backslash }}\,[0;3] = (3; + \infty )\)

+) \(\mathbb{R}\,{\rm{\backslash }}\,B = \mathbb{R}\,{\rm{\backslash }}\,(2; + \infty ) = ( - \infty ;2]\)