Помогите 6sin^2x + 2sin^2 2x=5

1) 6 * (1-cos2x) / 2 + 2sin^2 2x=5

-2-3cos2x + 2sin^2 2x = 0

2-2cos^2 2x - 3cos2x - 2=0

Замена: cos2x = t

-2t^2-3t=0

t * (-2t - 3) = 0

t1=0 - 2t - 3 = 0 t2 = 3/2

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