(Defined in TRIGONO.BAS)
The ATN() function returns the arctangent of the argument. It is the inverse function of TAN.
DECLARE FUNCTION ATN AS FLOAT (x AS FLOAT) SHARED STATIC
Warning
You must include the TRIGONO.BAS library in your program to be able to access this function.
INCLUDE "trigono.bas" PRINT ATN(0.5) : REM will output 0.464088