Sets — Class 11 Mathematics

A set is a well-defined collection of distinct objects, so one can always decide whether a given object belongs to it. Sets are written in roster form, listing elements within braces, or in set-builder form, stating a common property such as . Special number sets recur throughout the book. The empty set has no element; a set is finite or infinite by its count . Two sets are equal when they have exactly the same elements, and means every element of lies in . Intervals like and are subsets of . Operations on sets — union , intersection , difference and complement with respect to a universal set — obey commutative, associative, distributive, idempotent and De Morgan's laws . Venn diagrams picture these relationships, making the theory of sets the foundation for relations, functions and probability that follow.