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():
       _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
           || /* Since glibc 2.19: */ _DEFAULT_SOURCE
           || /* Glibc versions <= 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 
   

CONFORMING TO

   C99, POSIX.1-2001, POSIX.1-2008.

   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 4.09 of the Linux man-pages project.  A
   description of the project, information about reporting bugs,  and  the
   latest     version     of     this    page,    can    be    found    at
   https://www.kernel.org/doc/man-pages/.

                              2016-03-15                           ASIN(3)

---

Free and Open Source Software