ASIN(3)

NAME
asin, asinf, asinl - arc sine function

SYNOPSIS
#include <math.h>

double asin(double x);
float asinf(float x);
long double asinl(long double x);

Link with -lm.

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

asinf(), asinl():
    _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
    or cc -std=c99

DESCRIPTION
The asin() function calculates the principal value of the arc sine of x; that is the value whose sine is x.

RETURN VALUE
On success, these functions return the principal value of the arc sine of x in radians; the return value is in the range [-pi/2, pi/2]. If x is a NaN, a NaN is returned. If x is +0 (-0), +0 (-0) is returned. If x is outside the range [-1, 1], a domain error occurs, and a NaN is returned.

ERRORS
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

The following errors can occur:

Domain error: x is outside the range [-1, 1]
    errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.

CONFORMING TO
C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO
acos(3), atan(3), atan2(3), casin(3), cos(3), sin(3), tan(3)

COLOPHON
This page is part of release 3.65 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.