ctg x=2. Найти sin4x, cos2x, tg4x ctg^2 x = (1 + cos2x)/( 1 — cos2x) (1 + cos2x)/(1 — cos2x) = 4 1 + cos2x = 4 — 4cos2x 5cos2x = 3 cos2x = 0,6 sin2x = (1 — 0,6^2)^(1/2) sin2x = 0,8 sin4x = 2 sin2x * cos2x = 2*0.6*0.8 = 0.96 cos4x = (1 - sin^24x) = 0.28 tg 4x = sin4x / cos4x = 0.96/0.28 =96/28 = 24/7 Ответ: sin4x = 0.96 cos2x = 0,6 tg 4x = 24/7