.\" Copyright (c) 1991 The Regents of the University of California.
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.\"     from: @(#)tanh.3	5.1 (Berkeley) 5/2/91
.\" $FreeBSD: src/lib/msun/man/tanh.3,v 1.10 2001/10/13 12:23:23 bde Exp $
.\"
.Dd May 2, 1991
.Dt TANH 3
.Os
.Sh NAME
.Nm tanh ,
.Nm tanhf
.Nd hyperbolic tangent functions
.Sh LIBRARY
.Lb libm
.Sh SYNOPSIS
.In math.h
.Ft double
.Fn tanh "double x"
.Ft float
.Fn tanhf "float x"
.Sh DESCRIPTION
The
.Fn tanh
and the
.Fn tanhf
functions compute the hyperbolic tangent of
.Fa x .
For a discussion of error due to roundoff, see
.Xr math 3 .
.Sh RETURN VALUES
The
.Fn tanh
and the
.Fn tanhf
functions return the hyperbolic tangent value.
.Sh SEE ALSO
.Xr acos 3 ,
.Xr asin 3 ,
.Xr atan 3 ,
.Xr atan2 3 ,
.Xr cos 3 ,
.Xr cosh 3 ,
.Xr math 3 ,
.Xr sin 3 ,
.Xr sinh 3 ,
.Xr tan 3
.Sh STANDARDS
The
.Fn tanh
function conforms to
.St -isoC .