Question Number 76075 by benjo last updated on 23/Dec/19
$$\mathrm{how}\:\mathrm{i}\:\mathrm{evaluate}\:\mathrm{sin}\left(\pi/\mathrm{7}\right)×\mathrm{sin}\left(\mathrm{2}\pi/\mathrm{7}\right)×\mathrm{sin}\left(\mathrm{3}\pi/\mathrm{7}\right)\: \\ $$$$\mathrm{please}\:\mathrm{help}\:\mathrm{me} \\ $$
Answered by john santuy last updated on 23/Dec/19