Question

Упростите:
(2cos^2a*tga)/(sin^2a-cos^2a)

Answer 1

$frac{2, cos^2acdot tga}{sin^2a-cos^2a} =frac{2, cos^2acdot frac{sina}{cosa}}{-(cos^2a-sin^2a)}=frac{2cdot cosacdot sina}{-cos2a}=-frac{sin2a}{cos2a}=-tg2a$