Answer: The union of two sets, A and B, is a set whose elements are those that appear in either Set A or Set B without repetition. Without repetition means that elements in both A and B need to be listed only once in the union. The union combines every element from Set A and Set B. The symbol for union is. The intersection of two sets, A and B, is a set whose elements are those that are common to A and B. This means the set includes only the elements that are found in both Set A and Set B. The symbol for intersection is.
Example of Union: If A = {. . ., -3, -2, -1} and B = {0, 1, 2, 3, . . .}, then A B = {. . ., -3, -2, -1, 0, 1, 2, 3, . . .}, or the Integers.
Example of intersection: If A = {1, 2, 3} and B = {2, 3, 4}, then A B = {2, 3}, the elements in both set A and set B.