Question Number 37885 by abdo mathsup 649 cc last updated on 19/Jun/18
$${find}\:\:\:\prod_{{k}=\mathrm{1}} ^{{n}} \:{cos}\left(\frac{{k}\pi}{\mathrm{2}{n}+\mathrm{1}}\right)\:\:{and}\:\prod_{{k}=\mathrm{1}} ^{{n}} \:{sin}\left(\frac{{k}\pi}{\mathrm{2}{n}+\mathrm{1}}\right) \\ $$