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

1. 3psilon

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

2. anonymous

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3. anonymous

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