\[1)\ f(x) = \left\{ \begin{matrix} \sin x;\ \ \ 0 \leq x \leq 3\pi \\ \sqrt{- x};\ \ \ \ \ \ \ \ \ \ \ \ \ \ x < 0 \\ \end{matrix} \right.\ \]
\[\textbf{а)}\ D(x) = ( - \infty;\ 3\pi\rbrack;\]
\[\textbf{б)}\ E(y) = \lbrack - 1;\ + \infty);\]
\[\textbf{в)}\ ( - \infty;\ 0\rbrack \cup \left\lbrack \frac{\pi}{2};\ \frac{3\pi}{2} \right\rbrack \cup \left\lbrack \frac{5\pi}{2};\ 3\pi \right\rbrack.\]
\[2)\ f(x) = \left\{ \begin{matrix} \sin x;\ \ \frac{\pi}{4} \leq x \leq 2\text{π\ \ \ \ } \\ \cos x;\ \ - 2\pi \leq x < \frac{\pi}{4} \\ \end{matrix} \right.\ \]
\[\textbf{а)}\ D(x) = \lbrack - 2\pi;\ 2\pi\rbrack;\]
\[\textbf{б)}\ E(y) = \lbrack - 1;\ 1\rbrack;\]
\[\textbf{в)}\ \lbrack - 2\pi;\ - \pi\rbrack \cup \left\lbrack 0;\ \frac{\pi}{4} \right\rbrack \cup \left\lbrack \frac{\pi}{2};\ \frac{3\pi}{2} \right\rbrack.\]