\[\boxed{\mathbf{758}\mathbf{.}}\]
\[1)\ y = \sin x + \cos x;\]
\[Ответ:\ \ x \in R.\]
\[2)\ y = \sin x + tg\ x;\]
\[Ответ:\ \ x \neq \frac{\pi}{2} + \pi n.\]
\[3)\ y = \sqrt{\sin x};\]
\[\sin x \geq 0\]
\[\arcsin 0 + 2\pi n \leq x \leq \pi - \arcsin 0 + 2\pi n.\]
\[Ответ:\ \ 2\pi n \leq x \leq \pi + 2\pi n.\]
\[4)\ y = \sqrt{\cos x};\]
\[\cos x \geq 0\]
\[- \arccos 0 + 2\pi n \leq x \leq \arccos 0 + 2\pi n.\]
\[Ответ:\ \]
\[- \frac{\pi}{2} + 2\pi n \leq x \leq \frac{\pi}{2} + 2\pi n.\]
\[5)\ y = \frac{2x}{2\sin x - 1};\]
\[2\sin x - 1 \neq 0\]
\[2\sin x \neq 1\]
\[\sin x \neq \frac{1}{2}\]
\[x \neq ( - 1)^{n} \bullet \arcsin\frac{1}{2} + \pi n\]
\[x \neq ( - 1)^{n} \bullet \frac{\pi}{6} + \pi n.\]
\[Ответ:\ \ x \neq ( - 1)^{n} \bullet \frac{\pi}{6} + \pi n.\]
\[6)\ y = \frac{\cos x}{2\sin^{2}x - \sin x};\]
\[2\sin^{2}x - \sin x \neq 0\]
\[\sin x \bullet \left( 2\sin x - 1 \right) \neq 0\]
\[\sin x \neq 0;\]
\[x \neq \arcsin 0 + \pi n = \pi n.\]
\[2\sin x - 1 \neq 0\]
\[2\sin x \neq 1\]
\[\sin x \neq \frac{1}{2}\]
\[x \neq ( - 1)^{n} \bullet \arcsin\frac{1}{2} + \pi n\]
\[x \neq ( - 1)^{n} \bullet \frac{\pi}{6} + \pi n.\]
\[Ответ:\ \ x \neq \pi n;\ \ \]
\[x \neq ( - 1)^{n} \bullet \frac{\pi}{6} + \pi n.\]