Question

How do you calculate `tan^-1(sqrt3)`?

Answer 1

Assuming by `tan^(-1)(sqrt(3))`you mean `arctan(sqrt(3))`

and not `1/(tan(sqrt(3))`

We are looking for a value `theta`
such that
`tan(theta) = sqrt(3)`
that is
`theta = arctan(tan(theta)) = arctan(sqrt(3))`

`tan(theta) = sqrt(3)`
is the `tan` of a standard triangle
with `theta = pi/3`

That is `arctan(sqrt(3)) = PI/3`