$7+12 \sqrt{3}$

$12-7 \sqrt{3}$

$12+7 \sqrt{3}$

$4 \pi$

$\left(0, \frac{\pi}{6}\right) \cup\left(\frac{5 \pi}{6}, 2 \pi\right)$

$\left(\frac{\pi}{8}, \frac{5 \pi}{6}\right)$

$\left(0, \frac{\pi}{8}\right) \cup\left(\frac{\pi}{6}, \frac{5 \pi}{6}\right)$

$\left(\frac{41 \pi}{48}, \pi\right)$

0

1

$\sqrt{2}$

$2 \sqrt{2}$

$f(x)$ is continuous $\forall \mathrm{x} \in \mathrm{R}$

$f(x)>0, \forall x>1$

$f(x)$ is not differentiable but continuous $\forall x \in \mathrm{R}$

$f(x)$ is not differentiable for two values of $x$