NAME
acosd(), acosdf(), acosdl(), acosdw(), acosdq() — degree-valued arccosine functions
SYNOPSIS
#include <math.h>
double acosd(double x);
float acosdf(float x);
HP Integrity Server Only
long double acosdl(long double x);
extended acosdw(extended x);
quad acosdq(quad x);
DESCRIPTION
acosd()
returns the degree-valued arccosine of
x,
in the range 0 to 180.
acosdf()
is a
float
version of
acosd();
it takes a
float
argument and returns a
float
result.
Integrity Server Only
acosdl()
is a
long double
version of
acosd();
it takes a
long double
argument and returns a
long double
result.
acosdw()
is an
extended
version of
acosd();
it takes an
extended
argument and returns an
extended
result.
acosdq()
is equivalent to
acosdl()
on HP-UX systems.
USAGE
To use these functions,
compile either with the default
-Ae
option or with the
-Aa
and
-D_HPUX_SOURCE
options.
To use (for Integrity servers)
acosdw()
or
acosdq(),
compile also with the
-fpwidetypes
option.
To use any of 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.
For more information, see the
HP-UX floating-point guide for HP Integrity servers
at the following site:
http://www.hp.com/go/fp.
RETURN VALUE
acosd()
returns +0.
If the magnitude of
x
is greater than one,
acosd()
returns NaN and raises the invalid exception.
If
x
is NaN,
acosd()
returns NaN.
ERRORS
If the magnitude of
x
is greater than one,
acosd()
sets
errno
to [EDOM].
Integrity Server Only
HP-UX libm functions on Integrity server do not set
errno
by default. For
errno
setting, compile with the
+Olibmerrno
option.
STANDARDS CONFORMANCE
These functions are not specified by any standard.
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