Show that `4 sin alpha.sin (alpha + pi/3) sin (alpha + 2pi/3) = sin 3alpha`

Show that 4sin alpha*sin(alpha+(pi)/(3))sin(alpha+2(pi)/(3))=sin3 alpha

prove that 4sin alpha*sin(alpha+(pi)/(3))*sin(alpha+(2 pi)/(3))=sin3 alpha

Prove that sin alpha+sin(alpha+2pi/3)+sin(alpha+4pi/3)=0

sin alpha+sin(alpha+((2pi)/3))+sin(alpha+((4pi)/3))=0

Prove that sinalpha+sin(alpha+(2pi)/3)+sin(alpha+(4pi)/3)=0 .

prove sin alpha+sin(alpha+(2pi)/3)+sin (alpha+(4pi)/3)=0

Prove the following : sin alpha+ sin (alpha+ (2 pi)/3)+ sin (alpha+ (4 pi)/3)=0 .

show that : sin^2 alpha + sin^2(alpha +( 2pi)/n) +sin^2(alpha +( 4pi)/n) + ..... n terms = n/2

( sin alpha sin 3alpha + sin 3alpha sin 7 alpha + sin 5 alpha sin 15 alpha )/( sin alpha cos 3 alpha + sin 3alpha cos 7 alpha + sin 5 alpha cos 15 alpha ) =

Show that sin^3alpha+sin^3(120^@+alpha)+sin^3(240^@+alpha)=-3/4sin3alpha