xref: /freebsd/lib/msun/man/tanpi.3 (revision 7ab1a32cd43cbae61ad4dd435d6a482bbf61cb52)
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25.Dd April 1, 2017
26.Dt TANPI 3
27.Os
28.Sh NAME
29.Nm tanpi ,
30.Nm tanpif ,
31.Nm tanpil
32.Nd half\(encycle tangent functions
33.Sh LIBRARY
34.Lb libm
35.Sh SYNOPSIS
36.In math.h
37.Ft double
38.Fn tanpi "double x"
39.Ft float
40.Fn tanpif "float x"
41.Ft long double
42.Fn tanpil "long double x"
43.Sh DESCRIPTION
44The
45.Fn tanpi ,
46.Fn tanpif ,
47and
48.Fn tanpil
49functions compute the tangent of
50.Fa "\(*p \(mu x"
51and measure angles in half-cycles.
52.Sh RETURN VALUES
53The
54.Fn tanpi ,
55.Fn tanpif ,
56and
57.Fn tanpil
58functions returns
59.Fn tan "\(*p \(mu x" .
60If \*(Bax\*(Ba \*(Ge 2^(p - 1)
61where p is the floating\(enpoint precision of
62.Ar x ,
63then the returned value is \*(Pm0 and it has no significance.
64.Sh SPECIAL VALUES
65.Bl -tag
66.It
67.Fn tanpi \*(Pm0
68returns \*(Pm0.
69.It
70.Fn tanpi \*(Pmn
71returns \*(Pm0 for positive integers
72.Ar n .
73.It
74.Fn tanpi \*(Pmn/2
75returns \*(Na for n > 0 and raises an FE_INVALID exception.
76.It
77.Fn tanpi \*(Pm\(if
78return an \*(Na and raises an FE_INVALID exception.
79.It
80.Fn tanpi \*(Na
81return an \*(Na and raises an FE_INVALID exception.
82.El
83.Sh SEE ALSO
84.Xr cos 3 ,
85.Xr cospi 3 ,
86.Xr fenv 3 ,
87.Xr math 3 ,
88.Xr sin 3 ,
89.Xr sinpi 3 ,
90.Xr tan 3
91.Sh AUTHORS
92The half\(encycle trignometric functions were written by
93.An Steven G. Kargl Aq Mt kargl@FreeBSD.org .
94.Sh STANDARDS
95These functions conform to
96IEEE Std 754\(tm\(en2008 ,
97\(dqIEEE Standard for Floating-Point Arithmetic\(dq
98and to
99ISO/IEC TS 18661-4 ,
100\(dqInformation technology \(em Programming languages, their environments,
101and system software interfaces \(em Floating\(enpoint extensions for
102C\(dq \(em Part 4: Supplementary functions.
103
104
105