1.
cos(x/3) =0 ;
x/3 =π/2 +π*n , n ∈
Z ;.
x =3π/2 +3π*n , n ∈ Z.
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2.
tq(3x/4 - π/4) =1 ;
3x/4 - π/4 = π/4 + π*n , n ∈ Z ;
3x - π = π+ 4π*n , n ∈ Z ;
x =2π/3 + (4π/3)*n , n ∈ Z.
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3.
2sin(3x +π/3) +√3 = 0 ;
sin(3x +π/3) = -(√3) /2 ; * * *3x +π/3 = (-1)^(n+1)*π/3 + π*n , n ∈ Z * * *
3x +π/3 = π -π/3+2π*n , n ∈ Z ⇔ x = π/9+(2π/3)*n , n ∈ Z ;
или
3x +π/3 = π+π/3+2π*n , n ∈ Z⇔ x = π/3+(2π/3)*n , n ∈ Z .