ATAN

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
CONFORMING TO
SEE ALSO

NAME

atan − arc tangent function

SYNOPSIS

#include <math.h>

double atan(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

SEE ALSO

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