Знайти tgx, якщо ctg(x-π/4)=4/3
Ctg(x - π/4) = 4/3, tgx - ? tg(x - π/4) = 3/4 (tgx - tgπ/4)/(1 + tgx*tgπ/4) = 3/4 (tgx - 1)/(1 + tgx) = 3/4 4(tgx - 1) = 3(1 + tgx) 4tgx -4 = 3 + 3tgx tgx = 7