Question

tg^2a+ctg^2a, если tga+ctga = 4

Answer 1

tg²α + Ctg²α = ?                tgα + Ctgα = 4

(tgα + Ctgα )² = 16
tg²α + 2tgαCtgα + Ctg²α = 16
tg²α + Ctg²α = 16 - 2 * 1 = 16 - 2 = 14
tg²α + Ctg²α = 14