.\" Copyright (c) 1985 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)asinh.3m	6.2 (Berkeley) 5/12/86
.\"
.TH ASINH 3  "May 12, 1986"
.UC 6
.SH NAME
asinh, acosh, atanh \- inverse hyperbolic functions
.SH SYNOPSIS
.nf
.ft B
#include <math.h>

double asinh(double \fIx\fP)
double acosh(double \fIx\fP)
double atanh(double \fIx\fP)
.ft R
.fi
.SH DESCRIPTION
These functions compute the designated inverse hyperbolic functions for real
arguments.
.SH DIAGNOSTICS
acosh(x) = NaN with signal if x < 1.
.br
acosh(NaN) = NaN without signal.
.PP
atanh(x) = NaN with signal if |x| > 1.
.br
atanh(\(+-1) = \(+-Inf with signal.
.br
atanh(NaN) = that NaN without signal.
.SH SEE ALSO
.BR math (3),
.BR exp (3).
.SH AUTHOR
W. Kahan, Kwok\-Choi Ng