- Foundations Of Sets And Functions

Set Way of Describing a Set There are three ways to describe a set Way of Description Definition Example (i) The Descriptive form In this method the set can be described in words. The set of natural numbers (ii) The Tabular form In this method the set is described by listing its elements with in brackets. (iii)Set Builder notation In this method a symbol or letter is used for an arbitrary member of the set and stating the property common to all the members of the set. Order of a Set The number of elements present in a set is called order of the set. Types of Sets (w.r.t. the order) Collection of well-defined objects is called set. Name of the Set Definition Example (i) Finite Set If a set has finite number of elements present in it. (ii) Infinite Set In a set has infinite number of elements present in it. (iii)Null Set or Empty Set or Void Set A set having no elements. It is denoted by . (iv) Singleton Set A set having only one element. Sets, Functions, & Groups CH-2 1, 2, 3.... 10 1, 2, 3, .... / 1 2x x R x /x x