Для функции f(x)=cos6x-sin6x, найдите f'(π/8)
Помогите решить!!!

f(x) = cos6x - sin6x

f'(x) = -6sin6x - 6cos6x

f'(π/8)  = -6sin(6π/8) - 6cos(6π/8) = -6[sin(3π/4) + cos(3π/4)] = -6(√2/2 - √2/2) = 0

Ответ: 0.