## Algebra and Trigonometry 10th Edition

False. $cos\frac{θ}{2}\gt0$
If $\frac{\pi}{2}\ltθ\lt\pi$, then $\frac{\pi}{4}\lt\frac{θ}{2}\lt\frac{\pi}{2}$. That is, $\frac{θ}{2}$ is in the Quadrant I. So: $cos\frac{θ}{2}\gt0$