√(0,5 + Sin²x) = 1 - Cos2x
√(0,5 + Sin²x) = 1 - (1 - 2Sin²x)
√(0,5 + Sin²x) = 1 - 1 + 2Sin²x
√(0,5 + Sin²x) = 2Sin²x |²
0,5 + Sin²x = 4Sin⁴x
8Sin⁴x - 2Sin²x -1 = 0
Sin²x = t
8t² -2t -1 = 0
t =(1 +-√9)/8
t₁ = 1/2 t₂ = -1/4
Sin²x = 1/2 Sin²x = -4
Sinx = √2/2 или Sinx = -√2/2 ∅
x = (-1)ⁿ π/4 + nπ, n ∈Z x = (-1)ⁿ⁺¹π/4 +nπ, n ∈Z