## Precalculus (6th Edition) Blitzer

$25^o$
RECALL: An angle $\theta$, where $-360^o \lt \theta \lt 0$, is coterminal with: $\theta+ 360^o$ Thus, theusing the formula above, given angle is coterminal with: $=-335^o + 360^o \\=25^o$ Thus, $-335^o$ is coterminal with $25^o$. $25^o$ is in Quadrant I so $-335^o$ is also in Quadrant I. RECALL: The following are the means on how to find the reference angle of an angle $\theta$ based on its position: (1) Quadrant I: $\theta$ (itself) (2) Quadrant II: $180^o-\theta$ (3) Quadrant III: $\theta - 180^o$ (4) Quadrant IV: $360^o-\theta$ Use formula (1) above to obtain: reference angle of $-335^o$ = reference angle of $25^o$, which is $25^o$.