Question

Решить 2sin 11n/12*cos 11n/12

Answer 1

Решение
2sin 11n/12*cos 11n/12 = sin(2*(11π12)) = sin(11π/6) = 
= sin[(12π/6 - π/6)] = sin(2π - π/6) = - sin(π/6) = - 1/2