## Calculus 8th Edition

a) $\frac{\pi}{6}$ b) $\pi$
a) Let $\sin^{-1}(0.5)=y$. Then, $\sin y= 0.5= \sin \frac{\pi}{6}$. $⇒y= \frac{\pi}{6}$. b) Let $\cos^{-1}(-1)=y$. Then, $\cos y= -1= \cos \pi$. $⇒ y= \pi$