\[1)\ y = 2\sqrt{x};\ \ \ y = 2\sqrt{6 - x};\]
\[2\sqrt{x} = 2\sqrt{6 - x}\]
\[\sqrt{x} = \sqrt{6 - x}\]
\[x = 6 - x\]
\[2x = 6\]
\[x = 3.\]
\[6 - x > 0;\ \ \ x < 6;\]
\[x > 0.\]
\[Угол\ между\ кривыми:\]
\[y^{'}(3) = \frac{2}{2\sqrt{x}} = \frac{1}{\sqrt{3}};\]
\[y^{'}(3) = \frac{- 2}{2\sqrt{6 - x}} = - \frac{1}{\sqrt{3}};\]
\[a = \frac{\pi}{6};\text{\ \ \ }\]
\[b = - \frac{\pi}{6};\]
\[c = \frac{\pi}{6} + \frac{\pi}{6} = \frac{\pi}{3}.\]
\[Ответ:\ \ \frac{\pi}{3}.\]
\[2)\ y = \sqrt{2x + 1},\ \ \ y = 1;\]
\[\sqrt{2x + 1} = 1;\]
\[2x + 1 = 1;\]
\[2x = 0;\]
\[x = 0.\]
\[2x + 1 > 0\]
\[x > - \frac{1}{2}.\]
\[Угол\ между\ кривыми:\]
\[y^{'}(0) = \frac{2}{2\sqrt{2x + 1}} = 1;\]
\[y^{'}(0) = 0;\]
\[a = \frac{\pi}{4};\text{\ \ \ }\]
\[b = 0;\]
\[c = \frac{\pi}{4} - 0 = \frac{\pi}{4}.\]
\[Ответ:\ \ \frac{\pi}{4}.\]