COT()
 Computes the cotangent
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 Syntax

     COT(<nArc>) --> nCoTangent

 Argument

     <nArc>  Designates a radian value for which the cotangent is
     determined.

 Returns

     COT() returns the cotangent of the value specified in <nArc>.

 Description

     COT() computes the cotangent of an angle measured in radians.

 Note

     .  If the values are specified in degrees, use the DTOR()
        function to convert them.

 Example

     Computes the cotangent:

     ? STR(COT(PI() /4), 18, 15)      // 1.000000000000000
     ? STR(COT(PI() /2), 18, 15)      // 0.000000000000000
     ? STR(COT(PI() /9), 18, 15)      // 2.747477419454622