1)sin3x=0,sinx≠0
x=πn/3,n∈z u x≠πk,k∈z
x=πn/3,n∈z ,n=3k,n U k∈z
2)4sinx/2cosx/2-√3/2cos²x/2+√3/2sin²x/2+sin²x/2+cos²x/2=0/cos²x/2
(√3/2+1)tg²x/2+4tgx+(1-√3/2)=0
tgx/2=a
(√3/2+1)a²+4a+(1-√3/2)=0
D=16-4(√3/2+1)(1-√3/2)=16-4*(1-3/4)=16-4*1/4=16-1=15
a1=(-4-√15)/(√3+2)⇒tgx/2=(-4-√15)/(√3+2)⇒x=2arctg(-4-√15)/(√3+2)+πn,n∈z
a2=(-4+√15)/(√3+2)⇒tgx/2=(-4+√15)/(√3+2)⇒x=2arctg(-4+√15)/(√3+2)+πk,k∈z