Question

$\cos( - 7.9\pi)tg( - 1.1\pi) - \sin5.6\pi \: ctg4.4\pi$
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Answer 1

$Cos(-7,9\pi)tg(-1,1\pi)-Sin5,6\pi Ctg4,4\pi=Cos(8\pi-\frac{\pi }{10})*(-tg(\pi+\frac{\pi }{10}))-Sin(6\pi-\frac{2\pi }{5})*Ctg(4\pi+\frac{2\pi }{5})=-Cos\frac{\pi }{10}tg\frac{\pi }{10}+Sin\frac{2\pi }{5}*Ctg\frac{2\pi }{5}=-Sin\frac{\pi }{10}+Cos\frac{2\pi }{5}$