Решите
4.sin3x/sinx=0

5.Cos4x/sin2x=sin4x/cos2x

4sin3x=0 U sinx≠03x=πn⇒x=πn/3,n∈z U x≠πk,k∈zx=πn/3,n∈z U n≠3k,k∈z5cos4x/sin2x-sin4x/cos2x=0(cos4xcos2x-sin4xsin2x)/sin2xcos2x=02cos6x/sin4x=0cos6x=0⇒6x=π/2+πn⇒x=π/12+πn/6,n∈z sin4x≠0⇒4x≠πk⇒x≠πk/4.k∈zx=π/12+πn/6,n∈z U n≠(3k-1)/2,k∈z

4sin3x=0 U sinx≠03x=pin⇒x=pin/3,n∈z U x≠pik,k∈zx=pin/3,n∈z U n≠3k,k∈z5cos4x/sin2x-sin4x/cos2x=0(cos4xcos2x-sin4xsin2x)/sin2xcos2x=02cos6x/sin4x=0cos6x=0⇒6x=pi/2+pin⇒x=pi/12+pin/6,n∈z sin4x≠0⇒4x≠pik⇒x≠pik/4.k∈zx=pi/12+pin/6,n∈z U n≠(3k-1)/2,k∈zpi-число пи (3,14)