## Trigonometry (10th Edition)

(a) $\sin{\frac{\pi}{2}} = 1$ (b) $\cos{\frac{\pi}{2}}=0$ (c) $\tan{\frac{\pi}{2}} \text{ is undefined}$
RECALL: In a unit circle, $\sin{s} = y \\\cos{s} = x \\\tan{s} =\frac{y}{x}$ The angle $\frac{\pi}{2}$ intersects the unit circle at the point $(0, 1)$. Thus, (a) $\sin{\frac{\pi}{2}} = 1$ (b) $\cos{\frac{\pi}{2}}=0$ (c) $\tan{\frac{\pi}{2}} = \frac{1}{0}, \text{ is undefined}$