Question Number 129242 by Adel last updated on 14/Jan/21
$$\mathrm{cot}^{\mathrm{2}} \frac{\pi}{\mathrm{7}}+\mathrm{cot}^{\mathrm{2}} \frac{\mathrm{2}\pi}{\mathrm{7}}+\mathrm{cot}^{\mathrm{2}} \frac{\mathrm{7}\pi}{\mathrm{2}}=? \\ $$$$\mathrm{answer}\:\:\mathrm{by}\:\mathrm{solve} \\ $$
Commented by liberty last updated on 14/Jan/21
$$\mathrm{qn}\:\mathrm{128582} \\ $$