    1. Chapter 1 Class 11 Sets
2. Serial order wise
3. Ex 1.2

Transcript

Ex 1.2 , 1 Which of the following are examples of the null set (i) Set of odd natural numbers divisible by 2 Natural numbers = 1,2,3,4,5,6, .. Odd natural numbers = 1,3,5,7,9, No odd number is divisible by 2, therefore no elements in this set. It is a null set. Ex 1.2 , 1 Which of the following are examples of the null set (ii) Set of even prime numbers Prime numbers = 2,3,5,7,11,13,17, . Here, 2 is even. So, 2 is an even prime number. The set is not empty. It is not a null set Ex 1.2 , 1 Which of the following are examples of the null set (iii) {x: x is a natural numbers, x < 5 and x > 7 } Natural numbers = 1,2,3,4,5,6, Natural numbers less than 5 (x < 5) = 1,2,3,4 Natural numbers greater than 7 (x > 7) = 8,9,10,11, . A number cannot be simultaneously less than 5 and greater than 7. Therefore no elements in this set. It is a null set Ex 1.2 , 1 Which of the following are examples of the null set (iv) {y: y is a point common to any two parallel lines} Parallel lines do not intersect. Hence, they have no common point. Therefore no elements in this set. It is a null set

Ex 1.2

Chapter 1 Class 11 Sets
Serial order wise 