Good Day,

I'm stuck on proving the following trigonometric identity:

(sin 2x + sin 4x + sin 6x) / (cos 2x + cos 4x + cos 6x) = tan 4x

I do hope that some one can give me some advice on how to prove this as I've been going at this for the past 2 days and I feel that I'm not getting anywhere near.

Thanks in advance.