Respuesta :

Answer:

θ = π/8, 7π/8, 9π/8, 15π/8

Step-by-step explanation:

cos 2θ= √ 2/2

basic angle = π /4

2θ= π/4

2π - π/4 = 7π/4,

π/4 + 2π = 9π/4,

7π/4 + 2π = 15π/4

θ = π/8, 7π/8, 9π/8, 15π/8