xref: /csrg-svn/lib/libm/common_source/acosh.3 (revision 61283)
1*61283Sbostic.\" Copyright (c) 1991, 1993
2*61283Sbostic.\"	The Regents of the University of California.  All rights reserved.
348918Scael.\"
449229Scael.\" %sccs.include.redist.roff%
548918Scael.\"
6*61283Sbostic.\"     @(#)acosh.3	8.1 (Berkeley) 06/04/93
748918Scael.\"
848918Scael.Dd
948918Scael.Dt ACOSH 3
1048918Scael.Os BSD 4.3
1148918Scael.Sh NAME
1248918Scael.Nm acosh
1348918Scael.Nd inverse hyperbolic cosine function
1448918Scael.Sh SYNOPSIS
1548918Scael.Fd #include <math.h>
1648918Scael.Ft double
1748918Scael.Fn acosh "double x"
1848918Scael.Sh DESCRIPTION
1948918ScaelThe
2048918Scael.Fn acosh
2148918Scaelfunction computes the inverse hyperbolic cosine
2248918Scaelof the real
2348918Scaelargument
2448918Scael.Ar x .
2548918ScaelFor a discussion of error due to roundoff, see
2648918Scael.Xr math 3 .
2748918Scael.Sh RETURN VALUES
2848918ScaelThe
2948918Scael.Fn acosh
3048918Scaelfunction
3148918Scaelreturns the inverse hyperbolic cosine of
3248918Scael.Ar x .
3348918ScaelOn the
3448918Scael.Tn VAX
3548918Scaeland
3648918Scael.Tn Tahoe ,
3748918Scaelif the argument is less than one
3848918Scael.Fn acosh
3948918Scaelsets the global variable
4048918Scael.Va errno
4148918Scaelto
4248918Scael.Er EDOM
4348918Scaeland
4448918Scaelcauses a reserved operand fault.
4548918Scael.Sh SEE ALSO
4648918Scael.Xr asinh 3 ,
4748918Scael.Xr atanh 3 ,
4848918Scael.Xr exp 3 ,
4948918Scael.Xr infnan 3
5048918Scael.Xr math 3 ,
5148918Scael.Sh HISTORY
5248918ScaelThe
5348918Scael.Fn acosh
5448918Scaelfunction appeared in
5548918Scael.Bx 4.3 .
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