ATN Function
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 Action

 Returns the arctangent of a numeric expression.


 Syntax

  ATN( numeric-expression)


 Remarks

 The argument  numeric-expression can be of any numeric type.

  ATN (arctangent) is the inverse of  TAN (tangent).  ATN takes the ratio of
 two sides of a right triangle ( numeric-expression) and returns the
 corresponding angle. The ratio is the ratio of the lengths of the side
 opposite the angle and the side adjacent to the angle.

 The result is given in radians and is in the range --2 to --2 radians,
 where - = 3.141593 and --2 radians = 90 degrees.  ATN is calculated in single
 precision if  numeric-expression is an integer or single-precision value. If
 you use any other numeric data type,  ATN is calculated in double precision.

 To convert values from degrees to radians, multiply the angle (in degrees)
 times --180
 (or .0174532925199433). To convert a radian value to degrees, multiply it by
 180-- (or 57.2957795130824). In both cases, - - 3.141593.


 See Also

  COS,  SIN,  TAN


 Example

 The following example first finds the tangent of PI-4 and then takes the
 arctangent of the value. The result is PI-4.

 CONST PI=3.141592653
 PRINT ATN(TAN(PI-4.0)), PI-4.0


 Output

 78539816325  .78539816325