Question

Объясните, пожалуйста. 1-2

Answer 1

$frac{4cos(3pi - beta )-sin(frac{3pi}{2}+beta )}{ 5cos( beta -pi )}= frac{-4cos beta -(-cos beta )}{5cos (pi -beta )} = frac{-4cos beta }{-5cosbeta }=frac{4}{5}\\\\ frac{56}{sin(-frac{27pi }{4})cos(frac{27pi}{4})} = frac{56}{-frac{1}{2}cdot sinfrac{2cdot 27pi }{4}} =-frac{112}{sinfrac{27pi }{2}}=-frac{112}{sin(12pi +pi +frac{pi}{2})}=\\=-frac{112}{sin(pi +frac{pi}{2})}=-frac{112}{sinfrac{3pi}{2}}=-frac{112}{-1}=112$