Question

A ∆ B = {x|_________}​

Answer 1

Answer:

A∆B which is called the symmetric difference between A and B is defined as (A-B)U(B-A). Now, A-B is the set of all elements which are in A but not in B. So, A - B = {1,2}. Similarly, B-A is the set of all elements which are in B but not in A.