NCERT Solutions
Class 11 Maths
Sets
Ex.1.1 Q.5
List all the elements of the following sets:
(1) A = {x: x is an odd natural number}
(2) B = {x: x is an integer, -
< x <
}
(3) C = {x: x is an integer, x2 ≤ 4}
(4) D = {x: x is a letter in the word “LOYAL”}
(5) E = {x: x is a month of a year not having 31 days}
(6) F = {x: x is a consonant in the English alphabet which proceeds k}.
(1) A = {x: x is an odd natural number} = {1, 3, 5, 7, 9, 11, ……...}
(2) B = {x: x is an integer, -
< x < 
}
- = -0.5 and = 4.5
So, B = {0, 1, 2, 3, 4}
(3) C = {x: x is an integer, x2 ≤ 4}
It can be seen that
(-1)2 = 1, (-2)2 = 4 ≤ 4, (-3)2 = 9 > 4
(0)2 = 0 ≤ 4
(1)2 = 1 ≤ 4
(2)2 = 4 ≤ 4
(3)2 = 9 > 4
So, C = {-2, -1, 0, 1, 2}
(4) D = {x: x is a letter in the word “LOYAL”} = {L, O, Y, A}
(5) E = {x: x is a month of a year not having 31 days}
= {February, April, June, September and November}
(6) F = {x: x is a consonant in the English alphabet which proceeds k}.
= {b, c, d, f, g, h, j}