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