1.\" Copyright (c) 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)asin.3 5.1 (Berkeley) 5/2/91 33.\" $Id: asin.3,v 1.1.1.1 1994/08/19 09:39:41 jkh Exp $ 34.\" 35.Dd May 2, 1991 36.Dt ASIN 3 37.Os 38.Sh NAME 39.Nm asin , 40.Nm asinf 41.Nd arc sine functions 42.Sh SYNOPSIS 43.Fd #include <math.h> 44.Ft double 45.Fn asin "double x" 46.Ft float 47.Fn asinf "float x" 48.Sh DESCRIPTION 49The 50.Fn asin 51and the 52.Fn asinf 53functions compute the principal value of the arc sine of 54.Fa x . 55A domain error occurs for arguments not in the range [-1, +1]. 56For a discussion of error due to roundoff, see 57.Xr math 3 . 58.Sh RETURN VALUES 59The 60.Fn asin 61and the 62.Fn asinf 63functions return the arc sine in the range 64.Bk -words 65.Bq -\*(Pi/2, +\*(Pi/2 66.Ek 67radians. 68On the 69.Tn VAX , 70and Tahoe , 71if: 72.Bd -unfilled -offset indent 73.Pf \&| Ns Ar x Ns \&| > 1 74.Ed 75.Pp 76the 77global variable 78.Va errno 79is set to 80.Er EDOM 81and 82a reserved operand fault generated. 83.Sh SEE ALSO 84.Xr acos 3 , 85.Xr atan 3 , 86.Xr atan2 3 , 87.Xr cos 3 , 88.Xr cosh 3 , 89.Xr sin 3 , 90.Xr sinh 3 , 91.Xr tan 3 , 92.Xr tanh 3 , 93.Xr math 3 94.Sh STANDARDS 95The 96.Fn asin 97function conforms to 98.St -ansiC . 99