Cos2x+3sin^2x=1,25 помогите

Решение

Cos2x+3sin^2x=1,25

1 - 2sin²x + 3sin² x = 1,25

sin ²x = 1 - 1,25

sin²x = 0,25

sin²x = 1/4

1) sinx = - 1/2

x = (-1) ^n*arcsin (- 1/2) + πk, k ∈ Z

x = (-1) ^ (n+1) * arcsin (1/2) + πk, k ∈ Z

x = (-1) ^ (n+1) * (π/6) + πk, k ∈ Z

2) sinx = 1/2

x₁ = (-1) ^n*arcsin (1/2) + πn, n ∈ Z

x₂ = (-1) ^n * (π/6) + πn, n ∈ Z