13a8617a8SJordan K. Hubbard.\" Copyright (c) 1991 The Regents of the University of California. 23a8617a8SJordan K. Hubbard.\" All rights reserved. 33a8617a8SJordan K. Hubbard.\" 43a8617a8SJordan K. Hubbard.\" Redistribution and use in source and binary forms, with or without 53a8617a8SJordan K. Hubbard.\" modification, are permitted provided that the following conditions 63a8617a8SJordan K. Hubbard.\" are met: 73a8617a8SJordan K. Hubbard.\" 1. Redistributions of source code must retain the above copyright 83a8617a8SJordan K. Hubbard.\" notice, this list of conditions and the following disclaimer. 93a8617a8SJordan K. Hubbard.\" 2. Redistributions in binary form must reproduce the above copyright 103a8617a8SJordan K. Hubbard.\" notice, this list of conditions and the following disclaimer in the 113a8617a8SJordan K. Hubbard.\" documentation and/or other materials provided with the distribution. 123a8617a8SJordan K. Hubbard.\" 4. Neither the name of the University nor the names of its contributors 133a8617a8SJordan K. Hubbard.\" may be used to endorse or promote products derived from this software 143a8617a8SJordan K. Hubbard.\" without specific prior written permission. 153a8617a8SJordan K. Hubbard.\" 163a8617a8SJordan K. Hubbard.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 173a8617a8SJordan K. Hubbard.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 183a8617a8SJordan K. Hubbard.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 193a8617a8SJordan K. Hubbard.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 203a8617a8SJordan K. Hubbard.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 213a8617a8SJordan K. Hubbard.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 223a8617a8SJordan K. Hubbard.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 233a8617a8SJordan K. Hubbard.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 243a8617a8SJordan K. Hubbard.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 253a8617a8SJordan K. Hubbard.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 263a8617a8SJordan K. Hubbard.\" SUCH DAMAGE. 273a8617a8SJordan K. Hubbard.\" 283a8617a8SJordan K. Hubbard.\" from: @(#)atan.3 5.1 (Berkeley) 5/2/91 297f3dea24SPeter Wemm.\" $FreeBSD$ 303a8617a8SJordan K. Hubbard.\" 3117303c62SDavid Schultz.Dd July 31, 2008 323a8617a8SJordan K. Hubbard.Dt ATAN 3 333a8617a8SJordan K. Hubbard.Os 343a8617a8SJordan K. Hubbard.Sh NAME 357a15a32aSJordan K. Hubbard.Nm atan , 3617303c62SDavid Schultz.Nm atanf , 3717303c62SDavid Schultz.Nm atanl 387a15a32aSJordan K. Hubbard.Nd arc tangent functions of one variable 3964890443SBruce Evans.Sh LIBRARY 4064890443SBruce Evans.Lb libm 413a8617a8SJordan K. Hubbard.Sh SYNOPSIS 4232eef9aeSRuslan Ermilov.In math.h 433a8617a8SJordan K. Hubbard.Ft double 443a8617a8SJordan K. Hubbard.Fn atan "double x" 457a15a32aSJordan K. Hubbard.Ft float 467a15a32aSJordan K. Hubbard.Fn atanf "float x" 4717303c62SDavid Schultz.Ft long double 4817303c62SDavid Schultz.Fn atanl "long double x" 493a8617a8SJordan K. Hubbard.Sh DESCRIPTION 503a8617a8SJordan K. HubbardThe 5117303c62SDavid Schultz.Fn atan , 5217303c62SDavid Schultz.Fn atanf , 5317303c62SDavid Schultzand 5417303c62SDavid Schultz.Fn atanl 557a15a32aSJordan K. Hubbardfunctions compute the principal value of the arc tangent of 563a8617a8SJordan K. Hubbard.Fa x . 573a8617a8SJordan K. Hubbard.Sh RETURN VALUES 5817303c62SDavid SchultzThese functions return the arc tangent in the range 593a8617a8SJordan K. Hubbard.Bk -words 603a8617a8SJordan K. Hubbard.Bq -\*(Pi/2 , +\*(Pi/2 613a8617a8SJordan K. Hubbard.Ek 623a8617a8SJordan K. Hubbardradians. 633a8617a8SJordan K. Hubbard.Sh SEE ALSO 643a8617a8SJordan K. Hubbard.Xr acos 3 , 653a8617a8SJordan K. Hubbard.Xr asin 3 , 663a8617a8SJordan K. Hubbard.Xr atan2 3 , 673a8617a8SJordan K. Hubbard.Xr cos 3 , 683a8617a8SJordan K. Hubbard.Xr cosh 3 , 6975141cc9SWolfram Schneider.Xr math 3 , 703a8617a8SJordan K. Hubbard.Xr sin 3 , 713a8617a8SJordan K. Hubbard.Xr sinh 3 , 723a8617a8SJordan K. Hubbard.Xr tan 3 , 7375141cc9SWolfram Schneider.Xr tanh 3 743a8617a8SJordan K. Hubbard.Sh STANDARDS 753a8617a8SJordan K. HubbardThe 7617303c62SDavid Schultz.Fn atan , 7717303c62SDavid Schultz.Fn atanf , 7817303c62SDavid Schultzand 7917303c62SDavid Schultz.Fn atanl 8017303c62SDavid Schultzfunctions conform to 8117303c62SDavid Schultz.St -isoC-99 . 82