1.\" Copyright (c) 1991 Regents of the University of California.
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\" notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\" notice, this list of conditions and the following disclaimer in the
11.\" documentation and/or other materials provided with the distribution.
12.\" 3. All advertising materials mentioning features or use of this software
13.\" must display the following acknowledgement:
14.\" This product includes software developed by the University of
15.\" California, Berkeley and its contributors.
16.\" 4. Neither the name of the University nor the names of its contributors
17.\" may be used to endorse or promote products derived from this software
18.\" without specific prior written permission.
19.\"
20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30.\" SUCH DAMAGE.
31.\"
32.\" from: @(#)acosh.3 5.2 (Berkeley) 5/6/91
33.\" $Id: acosh.3,v 1.1.1.1 1994/08/19 09:39:41 jkh Exp $
34.\"
35.Dd May 6, 1991
36.Dt ACOSH 3
37.Os BSD 4.3
38.Sh NAME
39.Nm acosh ,
40.Nm acoshf
41.Nd inverse hyperbolic cosine functions
42.Sh SYNOPSIS
43.Fd #include <math.h>
44.Ft double
45.Fn acosh "double x"
46.Ft float
47.Fn acoshf "float x"
48.Sh DESCRIPTION
49The
50.Fn acosh
51and the
52.Fn acoshf
53functions compute the inverse hyperbolic cosine
54of the real
55argument
56.Ar x .
57For a discussion of error due to roundoff, see
58.Xr math 3 .
59.Sh RETURN VALUES
60The
61.Fn acosh
62and the
63.Fn acoshf
64functions
65return the inverse hyperbolic cosine of
66.Ar x .
67On the
68.Tn VAX
69and
70.Tn Tahoe ,
71if the argument is less than one
72.Fn acosh
73sets the global variable
74.Va errno
75to
76.Er EDOM
77and
78causes a reserved operand fault.
79.Sh SEE ALSO
80.Xr asinh 3 ,
81.Xr atanh 3 ,
82.Xr exp 3 ,
83.Xr infnan 3 ,
84.Xr math 3
85.Sh HISTORY
86The
87.Fn acosh
88function appeared in
89.Bx 4.3 .
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\" notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\" notice, this list of conditions and the following disclaimer in the
11.\" documentation and/or other materials provided with the distribution.
12.\" 3. All advertising materials mentioning features or use of this software
13.\" must display the following acknowledgement:
14.\" This product includes software developed by the University of
15.\" California, Berkeley and its contributors.
16.\" 4. Neither the name of the University nor the names of its contributors
17.\" may be used to endorse or promote products derived from this software
18.\" without specific prior written permission.
19.\"
20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30.\" SUCH DAMAGE.
31.\"
32.\" from: @(#)acosh.3 5.2 (Berkeley) 5/6/91
33.\" $Id: acosh.3,v 1.1.1.1 1994/08/19 09:39:41 jkh Exp $
34.\"
35.Dd May 6, 1991
36.Dt ACOSH 3
37.Os BSD 4.3
38.Sh NAME
39.Nm acosh ,
40.Nm acoshf
41.Nd inverse hyperbolic cosine functions
42.Sh SYNOPSIS
43.Fd #include <math.h>
44.Ft double
45.Fn acosh "double x"
46.Ft float
47.Fn acoshf "float x"
48.Sh DESCRIPTION
49The
50.Fn acosh
51and the
52.Fn acoshf
53functions compute the inverse hyperbolic cosine
54of the real
55argument
56.Ar x .
57For a discussion of error due to roundoff, see
58.Xr math 3 .
59.Sh RETURN VALUES
60The
61.Fn acosh
62and the
63.Fn acoshf
64functions
65return the inverse hyperbolic cosine of
66.Ar x .
67On the
68.Tn VAX
69and
70.Tn Tahoe ,
71if the argument is less than one
72.Fn acosh
73sets the global variable
74.Va errno
75to
76.Er EDOM
77and
78causes a reserved operand fault.
79.Sh SEE ALSO
80.Xr asinh 3 ,
81.Xr atanh 3 ,
82.Xr exp 3 ,
83.Xr infnan 3 ,
84.Xr math 3
85.Sh HISTORY
86The
87.Fn acosh
88function appeared in
89.Bx 4.3 .