Memory tip: ONE( Open No endpoint). Open windows = Light Closed Window = Dark() Looks like O, so it is used for Open interval [] looks like closed box, so it is used for closed interval
Venn Diagrams
Most of the relationships between sets can be represented by means of diagrams known as Venn diagrams. Venn diagrams are named after the, John Venn. These diagrams consist of rectangles and closed curves usually circles. The universal set is represented usually by a rectangle and its subsets by circles.
In the Venn diagram below: U = { 1,2,3,..., 10 } is the universal set of which A = { 2,4,6,8,10 } is a subset.
Operation on Sets 1. Union of sets 2. Intersection of sets 3. Difference of sets 4. Complement of a Set