Free Knowledge Resources


Linux Manual Pages


Free Software * Books

Source Code

Free Media

Linux

atanh(3)


NAME

   atanh, atanhf, atanhl - inverse hyperbolic tangent function

SYNOPSIS

   #include <math.h>

   double atanh(double x);
   float atanhf(float x);
   long double atanhl(long double x);

   Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

   atanh():
       _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
           || _XOPEN_SOURCE >= 500
           || /* Since glibc 2.19: */ _DEFAULT_SOURCE
           || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

   atanhf(), atanhl():
       _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
           || /* Since glibc 2.19: */ _DEFAULT_SOURCE
           || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION

   These  functions calculate the inverse hyperbolic tangent of x; that is
   the value whose hyperbolic tangent is x.

RETURN VALUE

   On success, these functions return the inverse hyperbolic tangent of x.

   If x is a NaN, a NaN is returned.

   If x is +0 (-0), +0 (-0) is returned.

   If x is +1 or -1,  a  pole  error  occurs,  and  the  functions  return
   HUGE_VAL,    HUGE_VALF,    or   HUGE_VALL,   respectively,   with   the
   mathematically correct sign.

   If the absolute value of x is greater than 1, a  domain  error  occurs,
   and a NaN is returned.

ERRORS

   See  math_error(7) for information on how to determine whether an error
   has occurred when calling these functions.

   The following errors can occur:

   Domain error: x less than -1 or greater than +1
          errno is set  to  EDOM.   An  invalid  floating-point  exception
          (FE_INVALID) is raised.

   Pole error: x is +1 or -1
          errno  is  set  to  ERANGE  (but  see  BUGS).   A divide-by-zero
          floating-point exception (FE_DIVBYZERO) is raised.

ATTRIBUTES

   For  an  explanation  of  the  terms  used   in   this   section,   see
   attributes(7).

   
   Interface                     Attribute      Value   
   
   atanh(), atanhf(), atanhl()   Thread safety  MT-Safe

CONFORMING TO

   C99, POSIX.1-2001, POSIX.1-2008.

   The variant returning double also conforms to SVr4, 4.3BSD, C89.

BUGS

   In  glibc  2.9  and  earlier, when a pole error occurs, errno as set to
   EDOM instead of the POSIX-mandated ERANGE.  Since version  2.10,  glibc
   does the right thing.

SEE ALSO

   acosh(3), asinh(3), catanh(3), cosh(3), sinh(3), tanh(3)

COLOPHON

   This  page  is  part of release 4.09 of the Linux man-pages project.  A
   description of the project, information about reporting bugs,  and  the
   latest     version     of     this    page,    can    be    found    at
   https://www.kernel.org/doc/man-pages/.

                              2016-03-15                          ATANH(3)



Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.



Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.



Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.



Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.


birds banner