8
sin(2x-π/6)=0
2x-π/6=πn
2x=π/6+πn
x=π/12+πn/2,n∈z
9
(tgπ/4-tgx)/(1+tgπ/4*tgx)=√3
tg(π/4-x)=π3
tg(x-π/4)=-√3
x-π/4=-π/3+πn
x=-π/12+πn,n∈z
10
sin(x/2-11π/28)=0
x/2-11π/28=πn
x/2=11π/28+πn
x=11π/14+2πn,n∈z
11
sin(4x-π/6)=-1
4x-π/6=-π/2+2πn
4x=-π/3+2πn
x=-π/12+πn/2,n∈z