Question

cos2x-0.25=cos^2x помогите пожалуйста

Answer 1

cos 2x= cos^2x-sin^2x

cos^2x-sin^2x-cos^2x=0.25

sin^2x=-1/4

sin x=1/2

sin x=-1/2

Answer 2

cos2x-0.25=cos²x

cos²х - sin²x - 0.25 = cos²x

sin²x = - 0.25

1) sinx = - 0.5

x₁ = (-1)^(k + 1) · π/6 + πk

2) sinx = 0.5

x₂ = (-1)^k · π/6 + πk