Question Number 45777 by habtetacke last updated on 16/Oct/18
$$\mathrm{2cos}\:\frac{\mathrm{3}\pi}{\mathrm{7}}=\frac{\mathrm{24}+\sqrt{\mathrm{3}{a}}}{\mathrm{72}}{where}\:{a}=−\mathrm{27}+\mathrm{4}\sqrt{\mathrm{147}.\mathrm{4}} \\ $$
Commented by MJS last updated on 17/Oct/18
$$\mathrm{what}'\mathrm{s}\:\mathrm{the}\:\mathrm{question}? \\ $$