Half-Angle Identities

Use a half-angle identity to find the exact value of  $\sin165\degree$  

Use a half-angle identity to find the exact value of  $\tan\left(\frac{5\pi}{8}\right)$  

Use a half-angle identity to find the exact value of  $\cot\left(\frac{7\pi}{12}\right)$  

Use a half-angle identity to find the exact value of  $\sec67.5\degree$  

 $\tan\theta=-\sqrt{14}$ and  $\frac{\pi}{2}<\theta<\pi$ find  $\cos\left(\frac{\theta}{2}\right)$  

 $\tan\theta=-2$ and  $90\degree<\theta<180\degree$ find  $\csc\left(\frac{\theta}{2}\right)$  

 $\cot\theta=\frac{12}{5}$ and  $180\degree<\theta<270\degree$ find  $\tan\left(\frac{\theta}{2}\right)$  

 $\csc\theta=-\sqrt{26}$ and  $270\degree<\theta<360\degree$ find  $\tan\left(\frac{\theta}{2}\right)$