## Algebra and Trigonometry 10th Edition

(a) See the graph. (b) Quadrant II (c) $\frac{2\pi}{3}$ and $-\frac{10\pi}{3}$
(b) A positive coterminal angle of $-\frac{4\pi}{3}$ is $\frac{2\pi}{3}$ $\frac{\pi}{2}\lt\frac{2\pi}{3}\lt\pi$, therefore, it lies in quadrant II. (c) $-\frac{4\pi}{3}+2\pi=\frac{2\pi}{3}$ $-\frac{4\pi}{3}-2\pi=-\frac{10\pi}{3}$