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2sinx+1=0

4cos (3x-п/4) = - √8

√3tg2/3x-1=0

ctg (x+п/6) = 1/3

2sin^2x-9cosx+3=0

(1+cosx2) (tgx-√3) = 0

1) sin x = - 1/2; x = (-1) ^n * (-Π/6) + Π*n

2) cos (3x-Π/4) = √2/2

3x-Π/4=Π/4+2Π*k; x1=Π/6+2Π/3*k

3x-Π/4=-Π/4+2Π*n; x2=2Π/3*n

3) tg (2x/3) = 1/√3

2x/3=Π/6+Π*k; x=Π/4+Π/2*k

4) ctg (x+Π/6) = 1/3; x=-Π/6+arcctg (1/3) + Π*k

5) 2sin^2 x - 9cos x + 3 = 0

2 - 2cos^2 x - 9cos x + 3 = 0

2cos^2 x + 9cos x - 5 = 0

(2cos x - 1) (cos x + 5) = 0

cos x = - 5; решений нет

cos x = 1/2; x = ±Π/3 + 2Π*k

6) (1 + cos x) (tg x - √3) = 0

cos x = - 1; x1 = Π + 2Π*k

tg x = √3; x = Π/3 + Π*n