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\" from: @(#)acosh.3 5.2 (Berkeley) 5/6/91
\" $NetBSD: acosh.3,v 1.18 2022/12/04 11:25:09 uwe Exp $
\"
Dd January 29, 2013
Dt ACOSH 3
Os
Sh NAME
Nm acosh ,
Nm acoshf ,
Nm acoshl
Nd inverse hyperbolic cosine function
Sh LIBRARY
Lb libm
Sh SYNOPSIS
In math.h
Ft double
Fn acosh "double x"
Ft float
Fn acoshf "float x"
Ft long double
Fn acoshl "long double x"
Sh DESCRIPTION
The
Fn acosh ,
Fn acoshf ,
and
Fn acoshl
functions compute the inverse hyperbolic cosine
of the real
argument
Ar x .
Sh RETURN VALUES
\" POSIX_MODE
If x is less than one,
Fn acosh "x" ,
Fn acoshf "x" ,
and
Fn acoshl "x"
return NaN and set the global variable
Va errno
to
Er EDOM .
\" SVR4_MODE
\" call
\" .Xr matherr 3 .
Sh SEE ALSO
Xr asinh 3 ,
Xr atanh 3 ,
Xr exp 3 ,
Xr math 3
\" .Xr matherr 3
Sh STANDARDS
The
Fn acosh
function conforms to
St -isoC-99 .
Sh HISTORY
The
Fn acosh
function appeared in
Bx 4.3 .
