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Command: atan2 | Section: 3 | Source: OpenBSD | File: atan2.3
ATAN2(3) FreeBSD Library Functions Manual ATAN2(3)
NAME
atan2, atan2f, atan2l - arc tangent functions of two variables
SYNOPSIS
#include <math.h>
double
atan2(double y, double x);
float
atan2f(float y, float x);
long double
atan2l(long double y, long double x);
DESCRIPTION
The atan2() function computes the principal value of the arc tangent of
y/x, using the signs of both arguments to determine the quadrant of the
return value. The atan2f() function is a single precision version of
atan2(). The atan2l() function is an extended precision version of
atan2().
RETURN VALUES
The atan2(), atan2f() and atan2l() functions, if successful, return the
arc tangent of y/x in the range [-pi, +pi] radians. If both x and y are
zero, the global variable errno is set to EDOM.
SEE ALSO
acos(3), asin(3), atan(3), cos(3), cosh(3), sin(3), sinh(3), tan(3),
tanh(3)
STANDARDS
The atan2() function conforms to ANSI X3.159-1989 ("ANSI C89").
FreeBSD 14.1-RELEASE-p8 June 29, 2021 FreeBSD 14.1-RELEASE-p8