Question

Помогите решить и объяснить,даю 35 балов

Answer 1

ctgh=1/tgh

tg2h=tgh/(1-(tgh)²)

Подставляем

(1/tgh - tgh)(tgh/(1-(tgh)²) =>

((1-(tgh)²)/tgh)(tgh/(1-(tgh)²))=1

Answer 2

$(ctg\alpha-tg\alpha)tg2\alpha=(\frac{cos\alpha} {sin\alpha}-\frac{sin\alpha} {cos\alpha})\frac{sin2\alpha}{cos2\alpha}=(\frac{cos^{2}\alpha-sin^{2}\alpha} {sin\alpha*cos\alpha})\frac{sin2\alpha}{cos2\alpha}=\frac{cos2\alpha} {sin\alpha*cos\alpha}*\frac{sin2\alpha}{cos2\alpha}=\frac{2sin\alpha*cos\alpha} {sin\alpha*cos\alpha}=2$