Question

qual a tangente do arco de -810°?​

Answer 1

$\boxed{\begin{array}{l}\rm -810^\circ=-2\cdot360^\circ-90^\circ\\\rm 360^\circ-90^\circ=270^\circ\\\rm tg(-810^\circ)=tg(270^\circ)=\not\exists\end{array}}$