Question

Упростите выражение 8sin^2a/1+tg^2a

Answer 1

$frac{8Sin^{2}alpha}{1+tg^{2}alpha}=frac{8Sin^{2}alpha}{frac{1}{Cos^{2}alpha}}=8Sin^{2}alpha Cos^{2}alpha=2*(4Sin^{2}alpha Cos^{2}alpha)=2Sin^{2}2alpha$