====== ATN ======

(Defined in //[[trigono.bas]]//)

The ''ATN()'' function returns the arctangent of the argument. It is the inverse function of [[TAN]].

===== Function header =====

  DECLARE FUNCTION ATN AS FLOAT (x AS FLOAT) SHARED STATIC

<adm warning>
You must include the //TRIGONO.BAS// library in your program to be able to access this function.
</adm>

===== Example =====

  INCLUDE "trigono.bas"
  PRINT ATN(0.5) : REM will output 0.464088

===== See also =====

  * [[TAN]]
  * [[SIN]]
  * [[COS]]