NAME
asin(), asinf() — arcsine functions
SYNOPSIS
#include <math.h>
double asin(double x);
float asinf(float x);
DESCRIPTION
asin()
returns the arcsine of
x
in the range -π/2 to π/2.
asinf()
is a
float
version of
asin();
it takes a
float
argument and returns a
float
result. To use this function, compile either with the default
-Ae
option or with the
-Aa
and
-D_HPUX_SOURCE
options.
asinf()
is not specified by any standard, but it is
named in accordance with the conventions
specified in the "Future Library Directions" section of the
ANSI C standard.
To use these functions, make sure your program includes
<math.h>,
and link in the math library by specifying
-lm
on the compiler or linker command line.
Millicode versions of the
asin()
function are available.
Millicode versions of math library functions are usually
faster than their counterparts in the standard library.
To use these versions, compile your program with the
+Olibcalls
or the
+Oaggressive
optimization option.
If an error occurs, the millicode versions return the value described
in the
RETURN VALUE
section, but do not set
errno.
For more information, see the
HP-UX Floating-Point Guide.
RETURN VALUE
If
x
is NaN,
asin()
returns NaN.
If the magnitude of
x
is greater than one,
asin()
returns NaN and sets
errno
to [EDOM].
ERRORS
If
asin()
fails,
errno
is set to the following value.
- [EDOM]
The magnitude of
x
is greater than one.
STANDARDS CONFORMANCE
asin(): SVID3, XPG4.2, ANSI C
