NAME
cosd(), cosdf() — degree-valued cosine functions
SYNOPSIS
#include <math.h>
double cosd(double x);
float cosdf(float x);
DESCRIPTION
The
cosd()
function is a degree-valued version of
cos().
It returns the cosine of
x
(x
specified in degrees).
The
cosd()
function may lose accuracy when
x
is far from zero.
The
cosdf()
function is a
float
version of
cosd();
it takes a
float
argument and returns a
float
result.
The
cosd()
and
cosdf()
functions are not specified by any standard, but
cosdf()
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 or ±INFINITY,
cosd()
returns NaN.
If the correct value after rounding would be smaller in magnitude than
MINDOUBLE,
cosd()
returns zero.
ERRORS
No errors are defined.
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