Question Number 49963 by maxmathsup by imad last updated on 12/Dec/18
$${find}\:\:{cos}\left(\frac{\pi}{\mathrm{7}}\right)\:{by}\:{solving}\:{the}\:{equation}\:{x}^{\mathrm{7}} −\mathrm{1}=\mathrm{0}\:{inside}\:{C}\:. \\ $$
find-cos-pi-7-by-solving-the-equation-x-7-1-0-inside-C-