1.\" $NetBSD: pow.3,v 1.4 2024/01/26 23:41:55 wiz Exp $ 2.\" 3.\" Copyright (c) 2011 Jukka Ruohonen <jruohonen@iki.fi> 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 16.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 17.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 19.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25.\" POSSIBILITY OF SUCH DAMAGE. 26.\" 27.Dd January 24, 2024 28.Dt POW 3 29.Os 30.Sh NAME 31.Nm pow , 32.Nm powf , 33.Nm powl 34.Nd power functions 35.Sh LIBRARY 36.Lb libm 37.Sh SYNOPSIS 38.In math.h 39.Ft double 40.Fn pow "double x" "double y" 41.Ft float 42.Fn powf "float x" "float y" 43.Ft long double 44.Fn powl "long double x" "long double y" 45.Sh DESCRIPTION 46The 47.Fn pow 48family of functions returns 49.Fa x 50raised to the power of 51.Fa y . 52.Pp 53If 54.Fa x 55is negative and 56.Fa y 57is not an integer, the global variable 58.Va errno 59is set to 60.Er EDOM , 61and on 62.Tn VAX 63a reserved operand fault is generated. 64A portable application should nevertheless ensure that 65.Fa y 66is an integer value whenever 67.Fa x 68is negative. 69.Sh RETURN VALUES 70.\" 71.\" XXX: List also the special return values? 72.\" 73Upon successful completion, the described functions return 74.Fa x^y . 75.Sh SEE ALSO 76.Xr exp 3 , 77.Xr log 3 78.Sh STANDARDS 79The described functions conform to 80.St -isoC-99 . 81.Sh HISTORY 82The history of the power functions dates back to 83.At v6 . 84