When is the set statement: (A⊕B) = (A ∪ B) true? "When is the set statement:

(A⊕B) = (A ∪ B)

a true statement? Is it true sometimes, never, or always? If it is sometimes, state the cases where it is."
How would you go about finding the answer to the question or ones like this one? 
Thanks for your time!

If you define $A \bigoplus B$ as Kevin did we see that it is true when $A \cap B = \emptyset$. This is because $$(A \cap B^{c}) \cup (B \cap A^{c}) = A \cup B - (A \cap B) = A \cup B.$$ This tells us that for $A \cap B \neq \emptyset$ they are not equal. 
