\[1)\ f(x) = \left\{ \begin{matrix} \text{tg\ x};\ \text{\ \ }\ \ \pi \leq x < \frac{3\pi}{2} \\ \sin x;\ \ \ - \pi \leq x < \pi \\ \end{matrix} \right.\ \]
\[\textbf{а)}\ D(x) = \left\lbrack - \pi;\ \frac{3\pi}{2} \right);\]
\[\textbf{б)}\ E(y) = \lbrack - 1;\ + \infty);\]
\[\textbf{в)}\ \left\lbrack - \frac{\pi}{2};\ \frac{\pi}{2} \right\rbrack \cup \left\lbrack \pi;\ \frac{3\pi}{2} \right).\]
\[2)\ f(x) = \left\{ \begin{matrix} \text{ctg\ x};\ \ \ \ - \pi < x < - \frac{\pi}{2} \\ \cos x;\ \ \ - \frac{\pi}{2} \leq x < \frac{3\pi}{2}\text{\ \ } \\ \end{matrix} \right.\ \]
\[f(x) = \text{ctg\ x};\]
\[\frac{3\pi}{2} \leq x < 2\pi.\]
\[\textbf{а)}\ D(x) = ( - \pi;\ 2\pi);\]
\[\textbf{б)}\ E(y) = ( - \infty;\ + \infty);\]
\[\textbf{в)}\left\lbrack - \frac{\pi}{2};\ 0 \right\rbrack \cup \left\lbrack \pi;\ \frac{3\pi}{2} \right\rbrack.\]