# How do you evaluate tan((8pi)/3)?

$- \sqrt{3}$
$\tan \left(\frac{8 \pi}{3}\right) = \tan \left(\frac{2 \pi}{3} + \frac{6 \pi}{3}\right) = \tan \left(\frac{2 \pi}{3} + 2 \pi\right) =$
$= \tan \left(\frac{2 \pi}{3}\right) = - \sqrt{3}$