Question

How do you evaluate `Arctan -sqrt3`?

Answer 1

`(2pi)/3 and (5pi)/3`

Explanation:

`tan x = - sqrt3`
Trig table of special arcs gives:
arc `x = (2pi)/3`
Trig unit circle gives another arc `x = (2pi)/3 + pi = (5pi)/3` that has the same tan value.