Answer
(a) $\frac{19\pi}{6}$
$-\frac{5\pi}{6}$
(b) $\frac{\pi}{6}$
$-\frac{23\pi}{6}$
Work Step by Step
(a) $\frac{7\pi}{6}+2\pi=\frac{7\pi}{6}+\frac{12\pi}{6}=\frac{19\pi}{6}$
$\frac{7\pi}{6}-2\pi=\frac{7\pi}{6}-\frac{12\pi}{6}=-\frac{5\pi}{6}$
(b) $-\frac{11\pi}{6}+2\pi=-\frac{11\pi}{6}+\frac{12\pi}{6}=\frac{\pi}{6}$
$-\frac{11\pi}{6}-2\pi=-\frac{11\pi}{6}-\frac{12\pi}{6}=-\frac{23\pi}{6}$
