SIN(x)^2·COS(x)^2 = 1/8
(SIN(x)·COS(x))^2 = 1/8
(1/2·SIN(2·x))^2 = 1/8
α = 2·x
(1/2·SIN(α))^2 = 1/8
SIN(α)^2/4 = 1/8
SIN(α)^2 = 1/2
SIN(α) = - √2/2 ∨ SIN(α) = √2/2
SIN(α) = - √2/2 : α = - pi/4 + 2·k·pi
SIN(α) = √2/2 : α = pi/4 + 2·k·pi
soluzione:
x = - pi/8 + k·pi ∨ x = pi/8 + k·pi