Question

.....////////____пomoгиte пoжaлyйcta ___пpoшyyyyyyy___

Answer 1

$1)(tg\alpha+Ctg\alpha)^{2}-(tg\alpha-Ctg\alpha)^{2}=\\\\=tg^{2}\alpha +2tg\alpha Ctg\alpha+Ctg^{2}\alpha-(tg^{2}\alpha -2tg\alpha Ctg\alpha+Ctg^{2}\alpha)=\\\\=tg^{2}\alpha +2tg\alpha Ctg\alpha+Ctg^{2}\alpha-tg^{2}\alpha +2tg\alpha Ctg\alpha-Ctg^{2}\alpha=4\underbrace{tg\alpha Ctg\alpha}_{1}=\boxed4\\\\2)5tg0^{0}+2Sin(-\frac{\pi }{6})-3Ctg(-\frac{\pi }{4})+4Cos(-\frac{\pi }{2})=\\\\=5*0-2Sin\frac{\pi }{6}++3Ctg\frac{\pi }{4} +4Cos\frac{\pi }{2}= -2*\frac{1}{2}+3*1+4*0=$$=-1+3=\boxed2\\\\\\3)Sin(-45^{0})+Cos(-45^{0})+2Sin(-30^{0})-4Cos(-60^{0})+5Ctg(-45^{0})=\\\\=-Sin45^{0}+Cos45^{0}-2Sin30^{0}-4Cos60^{0}-5Ctg45^{0}=\\\\=-\frac{\sqrt{2} }{2}+\frac{\sqrt{2} }{2}-2*\frac{1}{2}-4*\frac{1}{2} -5*1=-1-2-5=\boxed{-8}$