Answer
Please see below.
Work Step by Step
Please note that an interval containing two periods can be found by solving the following inequality:$$-\frac{\pi }{2} \lt x-\frac{\pi }{4} \lt \frac{3\pi }{2} \quad \Rightarrow \quad -\frac{\pi }{4} \lt x \lt \frac{7\pi }{4}$$
