Union of Sets

The union of two or more sets contains all the elements that are in either set and is denoted by the symbol ⋃. In a Venn diagram, the union is the region that belongs to either set.

Consider an example. U&={1,2,3,4,5,6,7,8,9} A&={1,2,3} B&={3,4,5,6} In this case, the union of A and B contains the numbers 1, 2, 3, 4, 5, and 6. Note that, although the number 3 belongs to both sets, in the union it is written only once. A ⋃ B = {1,2,3,4,5,6 } This example can be illustrated with a Venn diagram.