Решить уравнение: cos (x - п/4) = -1/2

Question

Решить уравнение: cos (x - п/4) = -1/2

Answer 1

X-π/4=+-2π/3+2πn
x=2π/3+π/4+2πn=11π/12+2πn
x=-2π/3+π/4+2πn=-7π/12+2πn