asin(3) Library Functions Manual asin(3)
NAME
asin, asinf, asinl - arc sine function
LIBRARY
Math library (libm, -lm)
SYNOPSIS
#include <math.h>
double asin(double x);
float asinf(float x);
long double asinl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
asinf(), asinl():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
DESCRIPTION
These functions calculate 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.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
┌────────────────────────────────────────────┬───────────────┬─────────┐
│ Interface │ Attribute │ Value │
├────────────────────────────────────────────┼───────────────┼─────────┤
│ asin(), asinf(), asinl() │ Thread safety │ MT-Safe │
└────────────────────────────────────────────┴───────────────┴─────────┘
STANDARDS
C11, POSIX.1-2008.
HISTORY
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)
Linux man-pages 6.9.1 2024-05-02 asin(3)
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