NAME
acosd(), acosdf() — degree-valued arccosine functions
SYNOPSIS
#include <math.h>
double acosd(double x);
float acosdf(float x);
DESCRIPTION
acosd()
is a degree-valued version of the
acos()
function. It returns the 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.
To use this function, compile either with the default
-Ae
option or with the
-Aa
and
-D_HPUX_SOURCE
options.
Otherwise, the compiler will not find a correct declaration of
acosdf(),
and error messages or incorrect results will occur.
acosd()
and
acosdf()
are not specified by any standard, but
acosdf()
is named in accordance with the conventions
specified in the "Future Library Directions" section of the
ANSI C standard.
To use these functions, link in the math library by specifying
-lm
on the compiler or linker command line.
RETURN VALUE
If
x
is NaN,
acosd()
returns NaN.
If the magnitude of
x
is greater than one,
acosd()
returns zero and sets
errno
to [EDOM].
ERRORS
If
acosd()
fails,
errno
is set to the following value.
- [EDOM]
The magnitude of
x
is greater than one.
Printable version
