Computes $\operatorname{acot}(x)u/(2\pi)$, the arccotangent of a primitive float measured in
$u$ths of a turn (so that u = 360 gives degrees), returning the result as a primitive float.
Computes $\operatorname{acot}(x)u/(2\pi)$, the arccotangent of a Rational measured in $u$ths
of a turn (so that u = 360 gives degrees), returning the result as a primitive float.