$S=\left\{x\in\mathbb{R}\ |\ \dfrac{\pi}{6}

$S=\left\{x\in\mathbb{R}\ |\ \dfrac{\pi}{3}

$S=\left\{x\in\mathbb{R}\ |\ 0

$S=\left\{x\in\mathbb{R}\ |\ 0\le x<\dfrac{\pi}{6}\ \vee\ \dfrac{5\pi}{6}