I found a simple solution to sum a series with trigonometric functions by converting it into a telescoping sum, and posted an answer. However, the OP did not mention about telescoping in their question; what's more, the accepted answer does not rely on the concept, either (instead, it utilizes a summing of a geometric complex series).
The question was Proof explanation for a sum of sines (closed as a duplicate now).
So my question is: would it be appropriate to add the telescopic-series to the question..?
Taking into account that would be some kind of a self-promotion due to a connection with my answer more than with the original question...
I found a similar question here: Why shouldn't I add a tag to increase visibility?
However, I don't feel it answers my question clearly enough.