Помогите с тригонометрией,очень надо,решающая оценка

1 x/3=π/2+πn,n∈z⇒x=3π/2+3πn,n∈z 2 3x/4-π/4=π/4+πn,n∈z 3x/4=π/2+πn,n∈z x=2π/3+4πn/3,n∈z 3 sin(3x+π/3)=-√3/2 3x+π/3=(-1)^(n+1)*π/3+πn,n∈z 3x=-π/3+(-1)^(n+1)*π/3+πn,n∈z x-π/9+(-1)^(n+1)*π/9+πn/3,n∈z 4 {cosx≠√3/2 {sinx=-1/2 x=7π/6+2πn,n∈z 5 {sinx≠-√3/2 {cosx=1/2 x=π/6+2πn 6 {cos2x≠1 {cos3x=0 3x=π/2+πn,n∈z x=π/6+πn/3,n∈z 7 cos4x=-1⇒4x=π+2πn,n∈z⇒x=π/4+πn/2,n∈z sin2x=0⇒2x=πk⇒x=πk/2,k∈z 8 cos(x+π/4)=-1⇒x+π/4=π+2πn,n∈z⇒x=3π/4+2πn,n∈z tgx=-1⇒x=-π/4+πk,k∈z