`cos 15 x = sin 5x` if

cos15x=sin5x if

cos15x=sin5x if

sin 10 x = 2 sin 5x cos 5x

Prove that (sin x + sin 3x + sin 5x + sin 7x)/(cos x + cos 3x + cos 5x + cos 7x ) = tan 4x

The period of the function f(x) = (sin x + sin 3x - sin 5x + sin 7x)/(cos x + cos 3x + cos 5x + cos 7x) is

Prove that: ((sin 7x + sin 5x) + (sin 9x + sin 3x))/((cos7x + cos5x) + (cos9x + cos 3x))=tan 6x

Prove that (sin 7 x - sin 5x-sin3x +sin x)/(cos 7x-cos5x+cos3 x-cos x)=tan 2x

Prove that : (cos 9x - cos 5x)/(sin 17x -sin 3x)=- (sin 2x)/(cos 10x) .