overby.me
this repo has no description
1.\" Copyright (c) 2006 Apple Computer
2.\"
3.Dd December 11, 2006
4.Dt CACOS 3
5.Os BSD 4
6.Sh NAME
7.Nm cacos
8.Nd complex inverse cosine function
9.Sh SYNOPSIS
10.Ft double complex
11.Fn cacos "double complex z"
12.Ft long double complex
13.Fn cacosl "long double complex z"
14.Ft float complex
15.Fn cacosf "float complex z"
16.Sh DESCRIPTION
17.Fn cacos "z"
18computes the inverse cosine of the complex floating-point number
19.Fa z ,
20with branch cuts outside the interval
21.Bq -1,1
22along the real axis.
23.Pp
24.Fn cacos
25returns values in a strip of the complex plane with unbounded imaginary part, and real part in the interval
26.Bq 0, Pi .
27.Pp
28For all complex floating point numbers z, cacos(conj(z)) = conj(cacos(z)).
29.Sh SPECIAL VALUES
30The conjugate symmetry of cacos() is used to abbreviate the specification of special values.
31.Pp
32.Fn cacos "�0 + 0i"
33returns Pi/2 - 0i.
34.Pp
35.Fn cacos "�0 + NaN i"
36returns Pi/2 + NaN i.
37.Pp
38.Fn cacos "x + inf i"
39returns Pi/2 - inf i, for finite x.
40.Pp
41.Fn cacos "x + NaN i"
42returns NaN + NaN i, for finite nonzero x.
43.Pp
44.Fn cacos "-inf + yi"
45returns Pi - inf i, for finite positive-signed y.
46.Pp
47.Fn cacos "inf + yi"
48returns 0 - inf i, for finite positive-signed y.
49.Pp
50.Fn cacos "-inf + inf i"
51returns 3Pi/4 - inf i.
52.Pp
53.Fn cacos "inf + inf i"
54returns Pi/4 - inf i.
55.Pp
56.Fn cacos "�inf + NaN i"
57returns NaN + inf i.
58.Pp
59.Fn cacos "NaN + yi"
60returns NaN + NaN i, for finite y.
61.Pp
62.Fn cacos "NaN + inf i"
63returns NaN - inf i.
64.Pp
65.Fn cacos "NaN + NaN i"
66returns NaN + NaN i.
67.Sh NOTES
68.Sh SEE ALSO
69.Xr complex 3
70.Sh STANDARDS
71The
72.Fn cacos
73function conforms to ISO/IEC 9899:1999(E).