ASIN(3)                             Linux Programmer's Manual                             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 3.74 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 http://www.kernel.org/doc/man-pages/.



                                            2010-09-20                                    ASIN(3)