Тригонометрические уравнения

А) 37cos x + 5sin^2 x + 5cos^2 x=4

Б) cos^2 2x/37=3/4

А) 37cosx + 5sin²x + 5cos²x = 4

37cosx + 5 = 4

37cosx = - 1

cosx = - 1/37

x = ±arccos (-1/37) + 2πn, n ∈ Z

cos² (2x/37) = 3/4

cos (2x/37) = ±√3/2

cos (2x/37) = √3/2

2x/37 = ±π/6 + 2πn, n ∈ Z

x = ±37π/12 + 37πn, n ∈ Z

cos (2x/37) = - √3/2

2x/37 = ±5π/6 + 2πn, n ∈ Z

x = ±185π/3 + 37πn, n ∈ Z.