From the following picture:
we can find the values for the trigonometric functions for values as 30 and 60 degrees.
For instance, tan 30 is equal to
[tex]\tan 30=\frac{1}{\sqrt[]{3}}[/tex]Since
[tex]\frac{1}{\sqrt[]{3}}=\frac{\sqrt[]{3}}{3}[/tex]then,
[tex]\tan 30=\frac{\sqrt[]{3}}{3}[/tex]However, we have a minus sign, this imply the angle is negative. In other words,
[tex]\tan -30=-\frac{\sqrt[]{3}}{3}[/tex]Now, since -30 = 330, then we have
[tex]\tan 330=-\frac{\sqrt[]{3}}{3}[/tex]so the answer is
[tex]\theta=330\text{ }[/tex]