Дорый ночи помогите tg (2arcsin2/3); sin (2arccos1/4)

tg (2arcsin2/3) = sin (2arcsin2/3) / cos (2arcsin2/3) = (2sin (arcsin2/3) cos (arcsin2/3)) / (1-2sin^2 (arcsin2/3) = (4/3 (sqrt (1-4/9)) / (1-8/9) = (4/3*sqrt (5/9)) / (1/9) = 4sqrt (5)