Question

Докажите тождество
((Sin^2t+cos^2t)/(tg^2t*cos^2t))- (cos^2t/(1-cos^2t))=1

Answer 1

$frac{sin^2t+cos^2t}{tg^2t*cos^2t}-frac{cos^2t}{1-cos^2t}=\ frac{1}{sin^2t}-frac{cos^2t}{sin^2t}=frac{sin^2t}{sin^2t}=1$