For $0\leq{x}\leq{2\pi}$, $\sin x \text{ and } \cos x$ are both decreasing functions in the interval _________ .

1. $\left(0,\dfrac{\pi}{2}\right)$
2. $\left(\dfrac{\pi}{2},\pi\right)$
3. $\left(\pi,\dfrac{3\pi}{2}\right)$
4. $\left(\dfrac{3\pi}{2},2\pi\right)$