7. \( \sin(-319^\circ), \cos(\frac{15\pi}{7}), ctg (-341^\circ), tg(-\frac{12\pi}{5}) \)

* \( \sin(-319^\circ) = -\sin 319^\circ = -\sin(360^\circ - 41^\circ) = \sin 41^\circ \) * \( \cos(\frac{15\pi}{7}) = \cos(2\pi + \frac{\pi}{7}) = \cos(\frac{\pi}{7}) \) * \( ctg (-341^\circ) = -ctg 341^\circ = -ctg(360^\circ - 19^\circ) = ctg 19^\circ \) * \( tg(-\frac{12\pi}{5}) = -tg(\frac{12\pi}{5}) = -tg(2\pi + \frac{2\pi}{5}) = -tg(\frac{2\pi}{5}) \)