xref: /freebsd/lib/msun/man/asin.3 (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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28.\"     from: @(#)asin.3	5.1 (Berkeley) 5/2/91
29.\" $FreeBSD$
30.\"
31.Dd January 14, 2005
32.Dt ASIN 3
33.Os
34.Sh NAME
35.Nm asin ,
36.Nm asinf
37.Nd arc sine functions
38.Sh LIBRARY
39.Lb libm
40.Sh SYNOPSIS
41.In math.h
42.Ft double
43.Fn asin "double x"
44.Ft float
45.Fn asinf "float x"
46.Sh DESCRIPTION
47The
48.Fn asin
49and the
50.Fn asinf
51functions compute the principal value of the arc sine of
52.Fa x .
53A domain error occurs for arguments not in the range
54.Bq -1 , +1 .
55For a discussion of error due to roundoff, see
56.Xr math 3 .
57.Sh RETURN VALUES
58The
59.Fn asin
60and the
61.Fn asinf
62functions return the arc sine in the range
63.Bk -words
64.Bq -\*(Pi/2 , +\*(Pi/2
65.Ek
66radians.
67If:
68.Bd -unfilled -offset indent
69.Pf \&| Ns Ar x Ns \&| > 1
70.Ed
71.Pp
72.Fn asin x
73raises an invalid exception and returns an \*(Na.
74.Sh SEE ALSO
75.Xr acos 3 ,
76.Xr atan 3 ,
77.Xr atan2 3 ,
78.Xr cos 3 ,
79.Xr cosh 3 ,
80.Xr fenv 3 ,
81.Xr math 3 ,
82.Xr sin 3 ,
83.Xr sinh 3 ,
84.Xr tan 3 ,
85.Xr tanh 3
86.Sh STANDARDS
87The
88.Fn asin
89function conforms to
90.St -isoC .
91