ACOT (x) or
ACOT (y,x) (Minerva v1.90+ only)
The function ACOT, is the arc-cotangent function, that is to say the inverse of the cotangent function (COT in SuperBASIC): COT(ACOT(x))=x for all values of x, but due to the periodic nature of COT, ACOT(COT(x))=x is only true for where: 0<x<PI.
Note that if a negative value of x is provided, the angle returned will be the obtuse angle (ie. greater than 90 degrees).
ACOT can accept two parameters. If you specify two parameters then ACOT(y,x) will give the angle from the origin to the point (x,y). This is actually the same as ACOT(x/y) although it does also cater for when y=0 which would otherwise give an overflow error.
Please see the Mathematics section in the Appendix.
See also ARCOTH.