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.
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, compile either with the default
-Ae
option or with the
-Aa
and
-D_HPUX_SOURCE
options. Make sure your program includes
<math.h>.
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 NaN 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.
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