Cos function

  DECLARATION:  Cos(x : Real);

      PURPOSE:  Returns the Cosign of the argument.

         UNIT:  System

  RESULT TYPE:  Real

      REMARKS:  Where x is a real-type expression, the result will be
                the cosine of x.  x is assumed to represent an angle in
                radians.

      EXAMPLE:  Var
                   r : Real;

                Begin
                   r := Cos(Pi);
                End.