{"id":9600,"date":"2022-01-18T00:23:52","date_gmt":"2022-01-17T18:53:52","guid":{"rendered":"https:\/\/mathemerize.com\/?p=9600"},"modified":"2022-01-18T00:23:56","modified_gmt":"2022-01-17T18:53:56","slug":"union-of-sets-definition-and-venn-diagram-with-examples","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/union-of-sets-definition-and-venn-diagram-with-examples\/","title":{"rendered":"Union of Sets – Definition and Venn Diagram with Examples"},"content":{"rendered":"
Here you will learn what is the union of sets with definition and venn diagram representation and examples.<\/p>\n
Let’s begin –<\/p>\n
Definition<\/strong> : Let A and B be two sets. The union of A and B is the set of all those elements which belong either to A or to B or to both A and B.<\/p>\n We shall use the notation \\(A \\cup B\\) (read as “A union B”) to denote the union of A and B.<\/p>\n Thus, \\(A \\cup B\\) = {x : x \\(\\in\\) A or x \\(\\in\\) B}.<\/p>\n Clearly, x \\(\\in\\) \\(A \\cup B\\) \\(\\iff\\) x \\(\\in\\) A or x \\(\\in\\) B.<\/p>\n And, x \\(\\notin\\) \\(A \\cup B\\) \\(\\iff\\) x \\(\\notin\\) A or x \\(\\notin\\) B.<\/p>\n In the given figure whole shaded part represents \\(A \\cup B\\). This is the venn diagram for union of sets<\/strong>.<\/p>\n It is evident from the definition the A \\(\\subseteq\\) \\(A \\cup B\\), B\\(\\subseteq\\) \\(A \\cup B\\).<\/p>\n If A and B are two sets such that A \\(\\subset\\) B, then \\(A \\cup B\\) = B. Also, \\(A \\cup B\\) = A, if B\\(\\subset\\) A.<\/p>\n Example<\/strong><\/span> : If A = {1, 2, 3} and B = {1, 3, 5, 7}, then \\(A \\cup B\\) = {1, 2, 3, 5, 7}.<\/p>\n Example<\/strong><\/span> : If A = {1, 2, 3}, B = {3, 5} and C = {4, 7, 8}. Then \\(A \\cup B \\cup C\\) = {1, 2, 3, 4, 5, 7, 8}.<\/p>\n If A, B and C are finite sets, and U be the finite universal set, then<\/p>\n n(\\(A \\cup B\\)) = n(A) + n(B) – n(\\(A \\cap B\\))<\/p><\/blockquote>\n where, n(A) = number of elements in set A<\/p>\n n(B) = number of elements in set B<\/p>\n n(\\(A \\cap B\\)) = number of elements in intersection of sets A and B<\/p>\nFormula to Find Number of Elements in A Union B<\/h2>\n