1 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
2 .\" and Copyright (C) 2011 Michael Kerrisk <mtk.manpages@gamil.com>
3 .\" Distributed under GPL
5 .\" Japanese Version Copyright (c) 2003 Akihiro MOTOKI
6 .\" all rights reserved.
7 .\" Translated Wed Jul 23 05:24:21 JST 2003
8 .\" by Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
11 .\"WORD: arc cosine 逆余弦
12 .\"WORD: arc tangent 逆正接
14 .\"WORD: imaginary part 虚部
16 .TH CACOS 3 2011-09-15 "" "Linux Programmer's Manual"
18 .\"O cacos, cacosf, cacosl \- complex arc cosine
20 cacos, cacosf, cacosl \- 複素数の逆余弦 (arc cosine)
23 .B #include <complex.h>
25 .BI "double complex cacos(double complex " z );
27 .BI "float complex cacosf(float complex " z );
29 .BI "long double complex cacosl(long double complex " z );
31 .\"O Link with \fI\-lm\fP.
37 .\"O function calculates the complex arc cosine of
39 .\"O If \fIy\ =\ cacos(z)\fP, then \fIz\ =\ ccos(y)\fP.
42 .\"O is chosen in the interval [0,pi].
46 の逆余弦 (arc cosine) を計算する。
47 \fIy\ =\ cacos(z)\fP ならば、 \fIz\ =\ ccos(y)\fP が成立する。
49 の実部の値は区間 [0,pi] から選択される。
55 cacos(z) = \-i * clog(z + i * csqrt(1 \- z * z))
59 .\"O These functions first appeared in glibc in version 2.1.
60 これらの関数は glibc バージョン 2.1 で初めて登場した。
61 .\"O .SH "CONFORMING TO"
67 /* Link with "\-lm" */
75 main(int argc, char *argv[])
77 double complex z, c, f;
81 fprintf(stderr, "Usage: %s <real> <imag>\\n", argv[0]);
85 z = atof(argv[1]) + atof(argv[2]) * I;
89 printf("cacos() = %6.3f %6.3f*i\\n", creal(c), cimag(c));
91 f = \-i * clog(z + i * csqrt(1 \- z * z));
93 printf("formula = %6.3f %6.3f*i\\n", creal(f), cimag(f));