## 3psilon Group Title 180<theta<270 and cos(theta) = -.707 what is the value of tan(theta/2) one year ago one year ago

1. 3psilon

Why is the answer a negative? It is in the 3rd quadrant and tan is positive there

$\tan \frac{ \theta }{ 2 }=\frac{ \sin \frac{ \theta }{ 2 } }{ \cos \frac{ \theta }{ 2 } }=\frac{2\sin \theta \cos \theta}{\sqrt{\cos \theta+1}}$