The angle is in the 2nd quadrant, therefore:
The sin function is given by:
[tex]\sin (\theta)=\frac{opposite}{hypotenuse}=\frac{1}{3}[/tex]
Let's find the adjacent side using pythagorean theorem:
[tex]adjacent=\sqrt[]{3^2-1^2}=\sqrt[]{8}=2\sqrt[]{2}[/tex]
Therefore:
[tex]\sec (\theta)=\frac{hypotenuse}{adjacent}=-\frac{3}{2\sqrt[]{2}}=-\frac{3\sqrt[]{2}}{4}[/tex]
