Question

Пожалуйста Решите дам 30б​

Answer 1

$1)Ctg(-45^{0})*Cos225^{0}*Sin150^{0}=-Ctg45^{0}*Cos(180^{0}+45^{0})*Sin(180^{0}-30^{0})=\\\\=-Ctg45^{0}*(-Cos45^{0})*Sin30^{0}=1*\frac{\sqrt{2} }{2}*\frac{1}{2}=\boxed{\frac{\sqrt{2}}{4}}\\\\\\2)tg(-135^{0})*Cos300^{0}*Sin210^{0}=\\\\=-tg(180^{0}-45^{0})*Cos(360^{0}-60^{0})*Sin(180^{0}+30^{0})=\\\\=tg45^{0}*Cos60^{0}*(-Sin30^{0})=1*\frac{1}{2}*(-\frac{1}{2})=\boxed{-\frac{1}{4}}$

$3)Ctg(-\frac{3\pi }{4})*Cos150^{0}*Sin\frac{5\pi }{3}=-Ctg(\pi-\frac{\pi }{4})*Cos(180^{0}-30^{0} )*Sin(2\pi-\frac{\pi }{3})=\\\\=Ctg\frac{\pi }{4}*(-Cos30^{0})*(-Sin\frac{\pi }{3})=1*(-\frac{\sqrt{3} }{2})*(-\frac{\sqrt{3}}{2})=\boxed {\frac{3}{4}} \\\\\\4)Ctg(-225^{0}*Cos\frac{8\pi }{3}*Sin330^{0}=\\\\=-Ctg(180^{0}+45^{0})*Cos(3\pi-\frac{\pi }{3})*Sin(360^{0}-30^{0})=\\\\=-Ctg45^{0}*(-Cos\frac{\pi }{3})*(-Sin30^{0})=-1*(-\frac{1}{2})*(-\frac{1}{2})=\boxed{-\frac{1}{4}}$