1)sin(3x+π/4)=√3/2 ,3x+π/4=(-1)^k*π/3+πk , k⊂z
x=(-1)^k(π/9)-π/12+πk/3.
2)Cos(x/3-π/4)=-1/2, x/3-π/4=(+-)2π/3+2πk,k⊂z.
x/3=(+-)2π/3+π/4+2πk; x=(+-)2π+3π/4+6πk,k⊂z
Ответ. x=11π/4+6πk, или x=-5π/4+6πk, k∈z.
3) tg(x+π/3)=√3, x+π/3=π/3+πk, k∈z,
Ответ. x=πk, k⊂z.