Question

158 номер решите.......

Answer 1

$ctg alpha =3; ; Rightarrow ; ; frac{1}{sin^2 alpha }=1+ctg^2 alpha=1+3^2=10\\frac{2cos^2 alpha +3}{5+3cos^2 alpha }, |frac{:sin^2 alpha }{:sin^2 alpha }=frac{2ctg^2 alpha +frac{3}{sin^2 alpha }}{frac{5}{sin^2 alpha }+3ctg^2 alpha }=frac{2cdot 9+3cdot 10}{5cdot 10+3cdot 9}=frac{48}{77}$