man3/cos.3

   1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
   2 .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
   3 .\"     <mtk.manpages@gmail.com>
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  26 .\"
  27 .\" References consulted:
  28 .\"     Linux libc source code
  29 .\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
  30 .\"     386BSD man pages
  31 .\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu)
  32 .\" Modified 2002-07-27 by Walter Harms
  33 .\"     (walter.harms@informatik.uni-oldenburg.de)
  34 .TH COS 3 2017-09-15 ""   "Linux Programmer's Manual"
  35 .SH NAME
  36 cos, cosf, cosl \- cosine function
  37 .SH SYNOPSIS
  38 .nf
  39 .B #include <math.h>
  40 .PP
  41 .BI "double cos(double " x );
  42 .BI "float cosf(float " x );
  43 .BI "long double cosl(long double " x );
  44 .fi
  45 .PP
  46 Link with \fI\-lm\fP.
  47 .PP
  48 .in -4n
  49 Feature Test Macro Requirements for glibc (see
  50 .BR feature_test_macros (7)):
  51 .in
  52 .PP
  53 .ad l
  54 .BR cosf (),
  55 .BR cosl ():
  56 .RS 4
  57 _ISOC99_SOURCE || _POSIX_C_SOURCE\ >=\ 200112L
  58     || /* Since glibc 2.19: */ _DEFAULT_SOURCE
  59     || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
  60 .RE
  61 .ad
  62 .SH DESCRIPTION
  63 These functions return the cosine of
  64 .IR x ,
  65 where
  66 .I x
  67 is
  68 given in radians.
  69 .SH RETURN VALUE
  70 On success, these functions return the cosine of
  71 .IR x .
  72 .PP
  73 If
  74 .I x
  75 is a NaN, a NaN is returned.
  76 .PP
  77 If
  78 .I x
  79 is positive infinity or negative infinity,
  80 a domain error occurs,
  81 and a NaN is returned.
  82 .SH ERRORS
  83 See
  84 .BR math_error (7)
  85 for information on how to determine whether an error has occurred
  86 when calling these functions.
  87 .PP
  88 The following errors can occur:
  89 .TP
  90 Domain error: \fIx\fP is an infinity
  91 .I errno
  92 is set to
  93 .BR EDOM
  94 (but see BUGS).
  95 An invalid floating-point exception
  96 .RB ( FE_INVALID )
  97 is raised.
  98 .SH ATTRIBUTES
  99 For an explanation of the terms used in this section, see
 100 .BR attributes (7).
 101 .TS
 102 allbox;
 103 lbw21 lb lb
 104 l l l.
 105 Interface       Attribute       Value
 106 T{
 107 .BR cos (),
 108 .BR cosf (),
 109 .BR cosl ()
 110 T}      Thread safety   MT-Safe
 111 .TE
 112 .SH CONFORMING TO
 113 C99, POSIX.1-2001, POSIX.1-2008.
 114 .PP
 115 The variant returning
 116 .I double
 117 also conforms to
 118 SVr4, 4.3BSD.
 119 .SH BUGS
 120 Before version 2.10, the glibc implementation did not set
 121 .\" http://sources.redhat.com/bugzilla/show_bug.cgi?id=6780
 122 .I errno
 123 to
 124 .B EDOM
 125 when a domain error occurred.
 126 .SH SEE ALSO
 127 .BR acos (3),
 128 .BR asin (3),
 129 .BR atan (3),
 130 .BR atan2 (3),
 131 .BR ccos (3),
 132 .BR sin (3),
 133 .BR sincos (3),
 134 .BR tan (3)