Question

how do we know the value of
tan-5π/6

Answer 1

$\tan( - \frac{5\pi}{6} ) \\ = - \tan(150) \\ = - \tan(2 \times 90 - 30) \\ = - ( - \tan(30) ) \\ = \sqrt{3}$
Hope it will help you .

Answer 2

$\tan( - \frac{5\pi}{6} ) \\ = - \tan(150) \\ = - \tan(2 \times 90 - 30) \\ = - ( - \tan(30) ) \\ = \sqrt{3}$
Hope it will help you .