Question

inverse tangent sqrt3/3

Answer 1

\[\tan^{-1} \frac{ \sqrt{3} }{ 3 }\]
How?

Answer 2

\[\frac{ \sqrt{3} }{ 3 } = \frac{ 1 }{ \sqrt{3} }\]

Answer 3

Can you find the answer now?

Answer 4

***How?***

in general, you use a calculator. However, there are some angles that people memorize the sine , cosine and tangent
they are 0º, 30º, 45º, 60º and 90º
see http://www.analyzemath.com/trigonometry/special_angles.html

in your problem, you have one of these "special" angles