The negation of (~p∧q)∨(p∧~q) is
(p∨~q)∨(~p∨q)
(p∨~q)∧(~p∨q)
(p∧~q)∧(~p∨q)
(p∨~q)∧(p∨~q)
Let S:(~p∧q)∨(p∧~q)
⇒ ~S:∼((~p∧q)∨(p∧~q))⇒ ~S:∼(~p∧q)∧~(p∧~q) (De-Morgan's Law) ∴ ~S:(p∨~q)∧(~p∨q)