I am terribly disappointed that my question here has been marked as a duplicate.
Someone asked for a solution for a popular question that did not use complex arithmetics. Only one solution came close to giving a solution except that one step used a rather remarkable trigonometric identity without proof. For the sake of completion and understanding, I posted a question requesting a proof for this identity. Yes, this identity has appeared here before but, alas, the answers both used complex functions! So now my question has been closed for being a duplicate but I believe I'm asking a significantly different question.
I can not believe 5 people read my question (even with the clearly marked title) is still believe that it had 'already been answered.' Are voters even reading questions anymore or do they simply look at how similar the titles are?