Помогите пожалуйста с решением уравнения

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2(1 - sin^2(x)) - 3sin(x) = 0
2 - 2sin^2(x) - 3sin(x) = 0
2sin^2(x) + 3sin(x) - 2 = 0
sin(x) = y
2y^2 + 3y - 2 = 0
D = 9 + 16 = 25
y1 = (-3-5)/4 = -2 - не подходит, так как /cos/ <=1
y2 = (-3+5)/4 = 0.5
sin(x) = 0.5
x = (-1)^k p/6 + pk, k E Z
p/6 + pk = 9p/2
k = (9p/2 - p/6)/p = 13/3, k = 5
p/6 + pk = 11p/2
[k] = [(11p/2 - p/6)/p] = [16/3] = 5
x1 = p/6 + 5p = 31p/6