Question

ПОМОГИТЕ ПОЖАЛУЙСТА!!!ЗАРАНЕЕ СПАСИБО!!!

ВЛОЖЕНИЕ ВНУТРИ!!

 

Answer 1

$frac{ctg(270-alpha)}{1-tg^2(alpha-180)}*frac{ctg^2(360-alpha)-1}{ctg(180+alpha)}=frac{tgalpha}{1-tg^2alpha}*frac{ctg^2alpha-1}{ctgalpha}=$

$=frac{tgalpha}{tgalpha*ctgalpha-tg^2alpha}*frac{ctg^2alpha-tgalpha*ctgalpha}{ctgalpha}=frac{tgalpha}{tgalpha(ctgalpha-tgalpha)}*frac{ctgalpha(ctgalpha-tgalpha)}{ctgalpha}=1$

 

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