Question

Which of these sets is the null or singleton set
(a) A={x:x is not equal to x}​

Answer 1

(iii) C = {0}.

iv) The set of all triangles having four sides is a NULL ser

Explanation:

Complete question

Identify the following sets as null set or singleton set.

(i) A = {x : x ∈N, 1 < x < 2}

(ii) B = The set of all even natural numbers which are not divisible by 2

(iii) C = {0}.

(iv) D = The set of all triangles having four sides.

A null set is a set that contains no element while a singleton set is. a set that has only one element

The set C ={0} has just one element which is zero. This shows that the set is a singleton set

Also a triangle only has 3sides. No triangle can have 4sides. Hence the set of all triangles having four sides is a NULL SET