Sets

A set is a well

A set is a well-defined collection of objects. 'Well-defined' means we can clearly determine whether any given object belongs to the collection or not

In roster form

In roster form, all elements of a set are listed explicitly within braces {}, separated by commas. For example: (i) Set of even numbers less than 10:

In set

In set-builder form, we describe the property that all elements of a set must satisfy. The general format is {x : P(x)} where x is a variable and P(x)

The empty set (denoted φ

The empty set (denoted φ or {}) is a set that contains no elements. Examples of empty sets: (i) {x : 1 < x < 2, x is a natural number} = φ (no natural

A finite set has a definite

A finite set has a definite number of elements, denoted as n(S). Examples: n({1, 2, 3, 4, 5}) = 5, n({a, e, i, o, u}) = 5. An infinite set has infinit