Respuesta :

Answer:

x = 3π/4, 5π/4

Step-by-step explanation:

cos(x+2π) = -√2/2, [0,2π]

cos(x)cos(2π)-sin(x)sin(2π) = -√2/2

cos(x) = -√2/2

x = 3π/4, 5π/4

Remember that the cosine function is periodic, so cos(θ+2π)=cos(θ).