1 /* $OpenBSD: s_cacosh.c,v 1.8 2016/09/12 19:47:02 guenther Exp $ */
2 /*
3 * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 /* cacosh
19 *
20 * Complex inverse hyperbolic cosine
21 *
22 *
23 *
24 * SYNOPSIS:
25 *
26 * double complex cacosh();
27 * double complex z, w;
28 *
29 * w = cacosh (z);
30 *
31 *
32 *
33 * DESCRIPTION:
34 *
35 * acosh z = i acos z .
36 *
37 * ACCURACY:
38 *
39 * Relative error:
40 * arithmetic domain # trials peak rms
41 * IEEE -10,+10 30000 1.6e-14 2.1e-15
42 *
43 */
44
45 #include <complex.h>
46 #include <float.h>
47 #include <math.h>
48
49 double complex
cacosh(double complex z)50 cacosh(double complex z)
51 {
52 double complex w;
53
54 w = clog(z + csqrt(z + 1) * csqrt(z - 1));
55 return (w);
56 }
57 DEF_STD(cacosh);
58 LDBL_MAYBE_UNUSED_CLONE(cacosh);
59