EsiQuizz

$$ -\frac{\pi}{2}+\arctan \left(-\frac{5}{6}\right)$$ $$ -\frac{\pi}{2}+\arctan \left(\frac{5}{6}\right) $$ $$ \pi+\arctan \left(\frac{5}{6}\right)$$ $$ \frac{\pi}{2}+\arctan \left(\frac{5}{6}\right)$$