Chapter 1 - Section 1.4 - Predicates and Quantifiers - Exercises - Page 56: 50

Let P(x) be the statement that x is an even number and Q(x) be x is an odd number, where x denotes the domain of all positive integers. So $(\forall x P(x))$ and $(\forall x Q(x))$ are false. But $\forall x (P(x) \lor Q(x))$ will always be true, because x will always be either even or odd.

See answer.