Question

Вычислить: 1) cos (-45) 2) sin (-60) 3) ctg(-30) 4) tg (-45) 5) sin (-п/6) 6) ctg (-п/3)

Answer 1

$1)Cos(-45^{o})= Cos45^{0} =\frac{\sqrt{2} }{2}\\\\2)Sin(-60^{o})=-Sin60^{o} =-\frac{\sqrt{3} }{2}\\\\3)Ctg(-30^{o})=-Ctg30^{o}=-\sqrt{3}\\\\4)tg(-45^{o})=-tg45^{o} =-1\\\\5)Sin(-\frac{\pi }{6})=-Sin\frac{\pi }{6} =-\frac{1}{2}\\\\6)Ctg(-\frac{\pi }{3})=-Ctg\frac{\pi }{3}=-\frac{\sqrt{3} }{3}$