Question

Доказать тождества:

1) 1 - tg^2 x = (cos2x) / (cos^2 x)

 

2) ctg^2 x - 1 = (cos2x) / (sin^2 x)

Answer 1

1) 3 sin x + 2 cos x + 2;

2) 5 cos x – sin x + 5.

вырази