Tg(a)+Ctg(a)=3

Tg(a)-Ctg(a)

(tgα+ctgα)²=3²tg²α+ctg²α+2tgα ctgα=9tg²α+ctg²α+2=9tg²α+ctg²α=7(tgα-ctgα)²=tg²α+ctg²α-2tgα ctgα=tg²α+ctg²α-2⇒tg²α+ctg²α-2=7-2=5Ответ: 5