====== TAN ======

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

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

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

  DECLARE FUNCTION TAN 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 TAN(PI / 4) : REM outputs a number very close to 1, see below note

<adm note>
Trigonometric functions in XC=BASIC were designed to be fast rather than accurate. The result is accurate to 3 to 4 decimal digits (the error range is 0 to 0.0006). Please see [[http://www.ganssle.com/approx.htm|this article]] for details.
</adm>
===== See also =====

  * [[ATN]]
  * [[SIN]]
  * [[COS]]