2. \( \cos 295^\circ, \sin(-\frac{13\pi}{8}), ctg 447^\circ, tg(\frac{11\pi}{6}) \)

* \( \cos 295^\circ = \cos(360^\circ - 65^\circ) = \cos 65^\circ \) * \( \sin(-\frac{13\pi}{8}) = -\sin(\frac{13\pi}{8}) = -\sin(\pi + \frac{5\pi}{8}) = \sin(\frac{5\pi}{8}) = \sin(\pi - \frac{3\pi}{8}) = \sin(\frac{3\pi}{8}) \) * \( ctg 447^\circ = ctg(360^\circ + 87^\circ) = ctg 87^\circ \) * \( tg(\frac{11\pi}{6}) = tg(2\pi - \frac{\pi}{6}) = -tg(\frac{\pi}{6}) \)