Visualize the angle on the unit circle. What side ratio correspond with that angle? What quadrant is it in? (This will determine whether your answer will be positive or negative.)

$\frac{1}{2}$

See hint in part (a).

$\tan(a)=\frac{\text{sin}(a)}{\text{cos}(a)}$

$\sec(a)=\frac{1}{\text{cos}(a)}$