NAME
tand(), tandf() — degree-valued tangent functions
SYNOPSIS
#include <math.h>
double tand(double x);
float tandf(float x);
DESCRIPTION
tand()
is a degree-valued version of the
tan()
function. It returns the tangent of
x
(x
specified in degrees).
tand()
may lose accuracy when
x
is far from zero.
tandf()
is a
float
version of
tand();
it takes a
float
argument and returns a
float
result.
tand()
and
tandf()
are not specified by any standard, but
tandf()
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,
tand()
returns NaN.
If the correct value after rounding would be smaller in magnitude than
MINDOUBLE,
tand()
returns zero.
If the correct value would overflow,
tand()
returns
±HUGE_VAL
and sets
errno
to [ERANGE].
ERRORS
If
tand()
fails,
errno
is set to the following value.
- [ERANGE]
The correct value would overflow.
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