Let's assume we have two sets
First set is A
second set is B
we know that
Union of two sets is the set that contains elements or objects that belong to either A or to B or to both.
So, it does not leave any element from any set
So, for union of two sets to become null , sets A and B won't have any element
For example:
set A={ }
set B= { x : for all real value of x ,x^2 +1=0 }
Since, set B won't have any elements
so,
A∪B=Ф
Yes, the union of two sets have a solution of a null set........Answer