1.\" Copyright (c) 1985, 1991 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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" from: @(#)exp.3 6.12 (Berkeley) 7/31/91 29.\" $FreeBSD: src/lib/msun/man/exp.3,v 1.24 2008/01/18 21:43:00 das Exp $ 30.\" $NetBSD: exp.3,v 1.29 2012/11/06 21:43:37 dholland Exp $ 31.\" 32.Dd September 13, 2011 33.Dt EXP 3 34.Os 35.Sh NAME 36.Nm exp , 37.Nm expf , 38.\" The sorting error is intentional. exp and expf should be adjacent. 39.Nm exp2 , 40.Nm exp2f , 41.\" .Nm exp2l , 42.Nm expm1 , 43.Nm expm1f , 44.Nd exponential functions 45.Sh LIBRARY 46.Lb libm 47.Sh SYNOPSIS 48.In math.h 49.Ft double 50.Fn exp "double x" 51.Ft float 52.Fn expf "float x" 53.Ft double 54.Fn exp2 "double x" 55.Ft float 56.Fn exp2f "float x" 57.\" .Ft long double 58.\" .Fn exp2l "long double x" 59.Ft double 60.Fn expm1 "double x" 61.Ft float 62.Fn expm1f "float x" 63.Sh DESCRIPTION 64The 65.Fn exp 66and 67.Fn expf 68functions compute the base 69.Ms e 70exponential value of the given argument 71.Fa x . 72.Pp 73The 74.Fn exp2 75and 76.Fn exp2f 77.\" .Fn exp2f , 78.\" and 79.\" .Fn exp2l 80functions compute the base 2 exponential of the given argument 81.Fa x . 82.Pp 83The 84.Fn expm1 85and 86.Fn expm1f 87functions compute the value exp(x)\-1 accurately even for tiny argument 88.Fa x . 89.Sh RETURN VALUES 90These functions will return the appropriate computation unless an error 91occurs or an argument is out of range. 92The functions 93.Fn exp 94and 95.Fn expm1 96detect if the computed value will overflow, 97set the global variable 98.Va errno 99to 100.Er ERANGE 101and cause a reserved operand fault on a 102.Tn VAX . 103.Sh SEE ALSO 104.Xr math 3 105.Sh STANDARDS 106The 107.Fn exp 108functions conform to 109.St -ansiC . 110The 111.Fn exp2 , 112.Fn exp2f , 113.Fn expf , 114.Fn expm1 , 115and 116.Fn expm1f 117functions conform to 118.St -isoC-99 . 119.Sh HISTORY 120The 121.Fn exp 122functions appeared in 123.At v6 . 124The 125.Fn expm1 126function appeared in 127.Bx 4.3 . 128