## Trigonometry (11th Edition) Clone

$\theta=135^{\circ}$ or $225^{\circ}$
1. Since $sec\theta$ is negative, $\theta$ must be in quadrant II or III. 2. The absolute value of $sec\theta$ is $\sqrt 2$, therefore the reference angles is $45^{\circ}$. The actual angles in II and III quadrants are following: $180^{\circ}-45^{\circ}=135^{\circ}$ $180^{\circ}+45^{\circ}=225^{\circ}$