## Trigonometry 7th Edition

To find exact value of $\sec 300^{\circ}$, let's find its reference angle first. As $300^{\circ}$ terminates in quadrant IV, The reference angle = $360^{\circ} - 300^{\circ}$ = $60^{\circ}$ As $300^{\circ}$ terminates in quadrant IV, its $\sec$ will be positive. Therefore by reference angle theorem- $\sec 300^{\circ}$ = $\sec 60^{\circ}$ = 2