Find the general solutions of the following equations:
(i) $\sin x=\frac{1}{2}$
(ii) $\cos x=-\frac{\sqrt{3}}{2}$
(iii) $\operatorname{cosec} x=-\sqrt{2}$
(iv) $\sec x=\sqrt{2}$
(v) $\tan x=-\frac{1}{\sqrt{3}}$
(vi) $\sqrt{3} \sec x=2$
We have:
(i) $\sin x=\frac{1}{2}$
The value of $x$ satisfying $\sin x=\frac{1}{2}$ is $\frac{\pi}{6}$.
$\therefore \sin x=\frac{1}{2}$
$\Rightarrow \sin x=\sin \frac{\pi}{6}$
$\Rightarrow x=n \pi+(-1)^{n} \frac{\pi}{6}, n \in Z$
(ii) $\cos x=-\frac{\sqrt{3}}{2}$
The value of $x$ satisfying $\cos x=-\frac{\sqrt{3}}{2}$ is $\frac{7 \pi}{6}$.
$\therefore \cos x=-\frac{\sqrt{3}}{2}$
$\Rightarrow \cos x=\cos \frac{7 \pi}{6}$
$\Rightarrow x=2 n \pi \pm \frac{7 \pi}{6}, n \in Z$
(iii) $\operatorname{cosec} x=-\sqrt{2}$ (or) $\sin x=-\frac{1}{\sqrt{2}}$
The value of $x$ satisfying $\sin x=-\frac{1}{\sqrt{2}}$ is $-\frac{\pi}{4}$.
$\therefore \sin x=-\frac{1}{\sqrt{2}}$
$\Rightarrow \sin x=\sin \left(-\frac{\pi}{4}\right)$
$\Rightarrow x=n \pi+(-1)^{n}\left(-\frac{\pi}{4}\right), n \in Z$
$\Rightarrow x=n \pi+(-1)^{n+1} \frac{\pi}{4}, \mathrm{n} \in Z$
(iv) $\sec x=\sqrt{2}$ (or) $\cos x=\frac{1}{\sqrt{2}}$
The value of $x$ satisfying $\cos x=\frac{1}{\sqrt{2}}$ is $\frac{\pi}{4}$.
$\therefore \cos x=\frac{1}{\sqrt{2}}$
$\Rightarrow \cos x=\cos \frac{\pi}{4}$
$\Rightarrow x=2 n \pi \pm \frac{\pi}{4}, n \in Z$
(v) $\tan x=-\frac{1}{\sqrt{3}}$
The value of $x$ satisfying $\tan x=-\frac{1}{\sqrt{3}}$ is $-\frac{\pi}{6}$.
$\therefore \tan x=-\frac{1}{\sqrt{3}}$
$\Rightarrow \tan x=\tan \left(-\frac{\pi}{6}\right)$
$\Rightarrow x=n \pi-\frac{\pi}{6}, n \in Z$
(vi) $\sqrt{3} \sec x=2$
$\Rightarrow \sec x=\frac{2}{\sqrt{3}}$ (or) $\cos x=\frac{\sqrt{3}}{2}$
The value of $x$ satisfying $\cos x=\frac{\sqrt{3}}{2}$ is $\frac{\pi}{6}$.
$\therefore \cos x=\frac{\sqrt{3}}{2}$
$\Rightarrow \cos x=\cos \frac{\pi}{6}$
$\Rightarrow x=2 n \pi \pm \frac{\pi}{6}, n \in Z$