Решите 4.sin3x/sinx=0 5.Cos4x/sin2x=sin4x/cos2x

4
sin3x=0 U sinx≠0
3x=πn⇒x=πn/3,n∈z U x≠πk,k∈z
x=πn/3,n∈z U n≠3k,k∈z
5
cos4x/sin2x-sin4x/cos2x=0
(cos4xcos2x-sin4xsin2x)/sin2xcos2x=0
2cos6x/sin4x=0
cos6x=0⇒6x=π/2+πn⇒x=π/12+πn/6,n∈z
sin4x≠0⇒4x≠πk⇒x≠πk/4.k∈z
x=π/12+πn/6,n∈z U n≠(3k-1)/2,k∈z