ACOT

Syntax: ACOT (x)
     or ACOT (y,x)      (Minerva v1.90+ only)
Location: QL ROM

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 (greater than 90 degrees).

The angle returned is in radians.

MINERVA NOTE:
PRINT 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 anoverflow error.

CROSS-REFERENCE:
COT, ATAN, TAN.
See also ARCOTH.
