1.\" Copyright (c) 1985, 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.
--- 12 unchanged lines hidden (view full) ---
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\" from: @(#)atanh.3 5.2 (Berkeley) 5/6/91
29.\" $FreeBSD: head/lib/msun/man/atanh.3 165906 2007-01-09 01:02:06Z imp $
30.\"
31.Dd January 14, 2005
32.Dt ATANH 3
33.Os
34.Sh NAME
35.Nm atanh ,
36.Nm atanhf
37.Nd inverse hyperbolic tangent functions
38.Sh LIBRARY
39.Lb libm
40.Sh SYNOPSIS
41.In math.h
42.Ft double
43.Fn atanh "double x"
44.Ft float
45.Fn atanhf "float x"
46.Sh DESCRIPTION
47The
48.Fn atanh
49and the
50.Fn atanhf
51functions compute the inverse hyperbolic tangent
52of the real
53argument
54.Ar x .
55For a discussion of error due to roundoff, see
56.Xr math 3 .
57.Sh RETURN VALUES
58The
59.Fn atanh
60and the
61.Fn atanhf
62functions
63return the inverse hyperbolic tangent of
64.Ar x
65if successful.
66If the argument has absolute value 1, a divide-by-zero exception
67is raised and an infinity is returned.
68If
69.Ar |x|
70> 1, an invalid exception is raised and an \*(Na is returned.
71.Sh SEE ALSO
72.Xr acosh 3 ,
73.Xr asinh 3 ,
74.Xr exp 3 ,
75.Xr fenv 3 ,
76.Xr math 3
77.Sh HISTORY
78The
79.Fn atanh
80function appeared in
81.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.
--- 12 unchanged lines hidden (view full) ---
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\" from: @(#)atanh.3 5.2 (Berkeley) 5/6/91
29.\" $FreeBSD: head/lib/msun/man/atanh.3 165906 2007-01-09 01:02:06Z imp $
30.\"
31.Dd January 14, 2005
32.Dt ATANH 3
33.Os
34.Sh NAME
35.Nm atanh ,
36.Nm atanhf
37.Nd inverse hyperbolic tangent functions
38.Sh LIBRARY
39.Lb libm
40.Sh SYNOPSIS
41.In math.h
42.Ft double
43.Fn atanh "double x"
44.Ft float
45.Fn atanhf "float x"
46.Sh DESCRIPTION
47The
48.Fn atanh
49and the
50.Fn atanhf
51functions compute the inverse hyperbolic tangent
52of the real
53argument
54.Ar x .
55For a discussion of error due to roundoff, see
56.Xr math 3 .
57.Sh RETURN VALUES
58The
59.Fn atanh
60and the
61.Fn atanhf
62functions
63return the inverse hyperbolic tangent of
64.Ar x
65if successful.
66If the argument has absolute value 1, a divide-by-zero exception
67is raised and an infinity is returned.
68If
69.Ar |x|
70> 1, an invalid exception is raised and an \*(Na is returned.
71.Sh SEE ALSO
72.Xr acosh 3 ,
73.Xr asinh 3 ,
74.Xr exp 3 ,
75.Xr fenv 3 ,
76.Xr math 3
77.Sh HISTORY
78The
79.Fn atanh
80function appeared in
81.Bx 4.3 .