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

$(ctgalpha-tgalpha)tg2alpha=(frac{cosalpha} {sinalpha}-frac{sinalpha} {cosalpha})frac{sin2alpha}{cos2alpha}=(frac{cos^{2}alpha-sin^{2}alpha} {sinalpha*cosalpha})frac{sin2alpha}{cos2alpha}=frac{cos2alpha} {sinalpha*cosalpha}*frac{sin2alpha}{cos2alpha}=frac{2sinalpha*cosalpha} {sinalpha*cosalpha}=2$