atan

ATAN(3)			  Linux Programmer’s Manual		      ATAN(3)



NAME
       atan, atanf, atanl - arc tangent function

SYNOPSIS
       #include <math.h>

       double atan(double x);

       float atanf(float x);

       long double atanl( long double x);


DESCRIPTION
       The atan() function calculates the arc tangent of x; that is the value
       whose tangent is x.

RETURN VALUE
       The atan() function returns the arc tangent in radians and  the	value
       is mathematically defined to be between -PI/2 and PI/2 (inclusive).

CONFORMING TO
       SVID  3, POSIX, BSD 4.3, ISO 9899.  The float and long double variants
       are C99 requirements.

SEE ALSO
       acos(3), asin(3), atan2(3), cos(3), sin(3), tan(3)



				  2002-07-27			      ATAN(3)