ATAN(3) Linux Programmers Manual ATAN(3)
NAME
atan, atanf, atanl  arc tangent function
SYNOPSIS
#include
double atan(double x);
float atanf(float x);
long double atanl( long double x);
Link with lm.
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
SVr4, POSIX.12001, 4.3BSD, C89. The float and long double variants
are C99 requirements.
SEE ALSO
acos(3), asin(3), atan2(3), carg(3), catan(3), cos(3), sin(3), tan(3)
COLOPHON
This page is part of release 3.05 of the Linux manpages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/manpages/.
20020727 ATAN(3)
