mirror of https://github.com/mkerrisk/man-pages
126 lines
3.0 KiB
Groff
126 lines
3.0 KiB
Groff
.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
|
|
.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
|
|
.\" <mtk.manpages@gmail.com>
|
|
.\"
|
|
.\" %%%LICENSE_START(VERBATIM)
|
|
.\" Permission is granted to make and distribute verbatim copies of this
|
|
.\" manual provided the copyright notice and this permission notice are
|
|
.\" preserved on all copies.
|
|
.\"
|
|
.\" Permission is granted to copy and distribute modified versions of this
|
|
.\" manual under the conditions for verbatim copying, provided that the
|
|
.\" entire resulting derived work is distributed under the terms of a
|
|
.\" permission notice identical to this one.
|
|
.\"
|
|
.\" Since the Linux kernel and libraries are constantly changing, this
|
|
.\" manual page may be incorrect or out-of-date. The author(s) assume no
|
|
.\" responsibility for errors or omissions, or for damages resulting from
|
|
.\" the use of the information contained herein. The author(s) may not
|
|
.\" have taken the same level of care in the production of this manual,
|
|
.\" which is licensed free of charge, as they might when working
|
|
.\" professionally.
|
|
.\"
|
|
.\" Formatted or processed versions of this manual, if unaccompanied by
|
|
.\" the source, must acknowledge the copyright and authors of this work.
|
|
.\" %%%LICENSE_END
|
|
.\"
|
|
.\" References consulted:
|
|
.\" Linux libc source code
|
|
.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
|
|
.\" 386BSD man pages
|
|
.\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu)
|
|
.\" Modified 2002-07-27 by Walter Harms
|
|
.\" (walter.harms@informatik.uni-oldenburg.de)
|
|
.\"
|
|
.TH TANH 3 2015-04-19 "" "Linux Programmer's Manual"
|
|
.SH NAME
|
|
tanh, tanhf, tanhl \- hyperbolic tangent function
|
|
.SH SYNOPSIS
|
|
.nf
|
|
.B #include <math.h>
|
|
.sp
|
|
.BI "double tanh(double " x );
|
|
.br
|
|
.BI "float tanhf(float " x );
|
|
.br
|
|
.BI "long double tanhl(long double " x );
|
|
.fi
|
|
.sp
|
|
Link with \fI\-lm\fP.
|
|
.sp
|
|
.in -4n
|
|
Feature Test Macro Requirements for glibc (see
|
|
.BR feature_test_macros (7)):
|
|
.in
|
|
.sp
|
|
.ad l
|
|
.BR tanhf (),
|
|
.BR tanhl ():
|
|
.RS 4
|
|
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
|
|
_POSIX_C_SOURCE\ >=\ 200112L;
|
|
.br
|
|
or
|
|
.I cc\ -std=c99
|
|
.RE
|
|
.ad
|
|
.SH DESCRIPTION
|
|
These functions return the hyperbolic tangent of
|
|
.IR x ,
|
|
which
|
|
is defined mathematically as:
|
|
.nf
|
|
|
|
tanh(x) = sinh(x) / cosh(x)
|
|
.fi
|
|
.SH RETURN VALUE
|
|
On success, these functions return the hyperbolic tangent of
|
|
.IR x .
|
|
|
|
If
|
|
.I x
|
|
is a NaN, a NaN is returned.
|
|
|
|
If
|
|
.I x
|
|
is +0 (\-0), +0 (\-0) is returned.
|
|
|
|
If
|
|
.I x
|
|
is positive infinity (negative infinity),
|
|
+1 (\-1) is returned.
|
|
.\"
|
|
.\" POSIX.1-2001 documents an optional range error (underflow)
|
|
.\" for subnormal x;
|
|
.\" glibc 2.8 does not do this.
|
|
.SH ERRORS
|
|
No errors occur.
|
|
.SH ATTRIBUTES
|
|
For an explanation of the terms used in this section, see
|
|
.BR attributes (7).
|
|
.TS
|
|
allbox;
|
|
lbw24 lb lb
|
|
l l l.
|
|
Interface Attribute Value
|
|
T{
|
|
.BR tanh (),
|
|
.BR tanhf (),
|
|
.BR tanhl ()
|
|
T} Thread safety MT-Safe
|
|
.TE
|
|
.SH CONFORMING TO
|
|
C99, POSIX.1-2001, POSIX.1-2008.
|
|
|
|
The variant returning
|
|
.I double
|
|
also conforms to
|
|
SVr4, 4.3BSD, C89.
|
|
.SH SEE ALSO
|
|
.BR acosh (3),
|
|
.BR asinh (3),
|
|
.BR atanh (3),
|
|
.BR cosh (3),
|
|
.BR ctanh (3),
|
|
.BR sinh (3)
|