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59 lines
1.8 KiB
Plaintext
59 lines
1.8 KiB
Plaintext
NAME
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atanh - inverse hyperbolic tangent
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SYNOPSIS
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atanh(x [,eps])
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TYPES
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x real
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eps nonzero real, defaults to epsilon()
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return real
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DESCRIPTION
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Returns the atanh of x to a multiple of eps with error less in
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absolute value than .75 * eps.
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atanh(x) is the real number v for which tanh(v) = x. It is given by
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atanh(x) = ln((1 + x)/(1 - x))/2
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EXAMPLE
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> print atanh(.5,1e-5), atanh(.5,1e-10), atanh(.5,1e-15), atanh(.5,1e-20)
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.54931 .5493061443 .549306144334055 .5493061443340548457
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LIMITS
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none
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LINK LIBRARY
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NUMBER *qatanh(NUMBER *x, NUMBER *eps)
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SEE ALSO
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asinh, acosh, asech, acsch, acoth, epsilon
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## Copyright (C) 1999 Landon Curt Noll
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##
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## Calc is open software; you can redistribute it and/or modify it under
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## the terms of the version 2.1 of the GNU Lesser General Public License
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## as published by the Free Software Foundation.
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##
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## Calc is distributed in the hope that it will be useful, but WITHOUT
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## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
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## Public License for more details.
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##
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## A copy of version 2.1 of the GNU Lesser General Public License is
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## distributed with calc under the filename COPYING-LGPL. You should have
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## received a copy with calc; if not, write to Free Software Foundation, Inc.
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## 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
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##
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## @(#) $Revision: 29.1 $
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## @(#) $Id: atanh,v 29.1 1999/12/14 09:15:42 chongo Exp $
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## @(#) $Source: /usr/local/src/cmd/calc/help/RCS/atanh,v $
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##
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## Under source code control: 1994/03/19 01:40:27
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## File existed as early as: 1994
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##
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## chongo <was here> /\oo/\ http://reality.sgi.com/chongo/
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## Share and enjoy! :-) http://reality.sgi.com/chongo/tech/comp/calc/
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