Algebra: Chapter 9, Lesson 1, page 400.
Sets, Intersections and Unions
A set is a well-defined collection of objects called members or elements.
- Roster notation LISTS the members of the set.
- Set-Builder Notation gives a DESCRIPTION of how the set is built.
The intersection of 2 sets `A` and `B`, written `A ∩ B` is the set of all members that are COMMON to both sets. We say ” A intersection B”.
The union of 2 sets `A` and `B`, written `A ∪ B` is the set of all members that are in `A` or `B` or in both. If an intersection is EMPTY, we say the intersection is the empty set which is symbolized as `∅`.
All of these concepts are described here too with examples!