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: @(#)tan.3 5.1 (Berkeley) 5/2/91 33.\" $FreeBSD$ 34.\" 35.Dd May 2, 1991 36.Dt TAN 3 37.Os 38.Sh NAME 39.Nm tan , 40.Nm tanf 41.Nd tangent functions 42.Sh LIBRARY 43.Lb libm 44.Sh SYNOPSIS 45.In math.h 46.Ft double 47.Fn tan "double x" 48.Ft float 49.Fn tanf "float x" 50.Sh DESCRIPTION 51The 52.Fn tan 53and the 54.Fn tanf 55functions compute the tangent of 56.Fa x 57(measured in radians). 58A large magnitude argument may yield a result 59with little or no significance. 60For a discussion of error due to roundoff, see 61.Xr math 3 . 62.Sh RETURN VALUES 63The 64.Fn tan 65function returns the tangent value. 66.Sh SEE ALSO 67.Xr acos 3 , 68.Xr asin 3 , 69.Xr atan 3 , 70.Xr atan2 3 , 71.Xr cos 3 , 72.Xr cosh 3 , 73.Xr math 3 , 74.Xr sin 3 , 75.Xr sinh 3 , 76.Xr tanh 3 77.Sh STANDARDS 78The 79.Fn tan 80function conforms to 81.St -isoC . 82