34sinx=cosx (2cos^2)x=1-sinx 2sin4x-(2sin^2)x=1

1)34sinx-cosx=0/cosx
34tgx-1=0
tgx=1/34
x=arctg1/34+πn,n∈z
2)2-2sin²x-1+sinx=0
sinx=a
2a²-a-1=0
D=1+8=9
a1=(1-3)/4=-1/2⇒sinx=-1/2⇒x=(-1)^(n+1)*π/6+πn,n∈z
a2=(1+3)/4=1⇒sinx=1⇒x=π/2+2πk,k∈z
3)4sinxcosx-2sin²x-sin²x-cos²x=0/cos²x
3tg²x-4tgx+1=0
tgx=a
3a²-4a+1=0
D=16-12=4
a1=(4-2)/6=1/3⇒tgx=1/3⇒x=arctg1/3+πn,n∈z
a2=(4+2)/6=1⇒tgx=1⇒x=π/4+πk,k∈z