NCERT Book Class 11 Maths Sets Questions

1.1 Overview This chapter deals with the concept of a set, operations on sets.Concept of sets will be useful in studying the relations and functions.
1.1.1 Set and their representations A set is a well-defined collection of objects. There are two methods of representing a set
              (i) Roaster or tabular form (ii) Set builder form
1.1.2 The empty set A set which does not contain any element is called the empty set or the void set or null set and is denoted by { } or φ.
1.1.3 Finite and infinite sets A set which consists of a finite number of elements is called a finite set otherwise, the set is called an infinite set.
1.1.4 Subsets A set A is said to be a subset of set B if every element of A is also an element of B. In symbols we write A ⊂ B if a ∈ A ⇒ a ∈ B.
We denote     set of real numbers by R
                     set of natural numbers by N
                     set of integers by Z
                     set of rational numbers by Q
                     set of irrational numbers by T
We observe that
                     N ⊂ Z ⊂ Q ⊂ R,
                     T ⊂ R, Q ⊄ T, N ⊄ T
1.1.5 Equal sets Given two sets A and B, if every elements of A is also an element of B and if every element of B is also an element of A, then the sets A and B are said to be equal. The two equal sets will have exactly the same elements.

1.1.6 Intervals as subsets of R Let a, b ∈ R and a < b. Then

(a) An open interval denoted by (a, b) is the set of real numbers {x : a < x < b}
(b) A closed interval denoted by [a, b] is the set of real numbers {x : a ≤ x ≤ b)

Please refer to attached file for NCERT Class 11 Maths Sets Questions