Не могу решить sin(2arcsin1/3)

Решение tg (arcsin1/3) = sin(arcsin1/3) / cos(arcsin1/3)  1) sin(arcsin1/3) =1/3 2) cos²(arcsin1/3) = 1-sin²(arcsin1/3) = 1 - (1/3)² =1-1|9 =8/9, тогда cos(arcsin1/3) = √8/3 3) tg (arcsin1/3)= (1/3) : (√8/3) = 1/√8 = 1/2√2=√2/4