Question

упросттте выражение 3cos^2x+3cos^2x•tg^2x

Answer 1

$3cos^2x+3cos^2x*tg^2x=3cos^2x+3cos^2x* frac{sin^2x}{cos^2x} = \ \ =3cos^2x+3sin^2x=3(sin^2x+cos^2x)=3*1=3$