.\"	$OpenBSD: ctanh.3,v 1.2 2013/06/05 03:40:26 tedu Exp $
.\"
.\" Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
.\"
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.Dd $Mdocdate: June 5 2013 $
.Dt CTANH 3
.Os
.Sh NAME
.Nm ctanh ,
.Nm ctanhf ,
.Nm ctanhl
.Nd complex hyperbolic tangent
.Sh SYNOPSIS
.In complex.h
.Ft double complex
.Fn ctanh "double complex z"
.Ft float complex
.Fn ctanhf "float complex z"
.Ft long double complex
.Fn ctanhl "long double complex z"
.Sh DESCRIPTION
The
.Fn ctanh ,
.Fn ctanhf
and
.Fn ctanhl
functions compute the complex hyperbolic tangent of
.Fa z .
.Pp
If
.Fa z
= x + iy, then
.Bd -literal -offset indent
ctanh(z) = (sinh(2x) + i sin(2y)) / (cosh(2x) + cos(2y)).
.Ed
.Sh RETURN VALUES
The
.Fn ctanh ,
.Fn ctanhf
and
.Fn ctanhl
functions return the complex hyperbolic tangent of
.Fa z .
.Sh SEE ALSO
.Xr ccosh 3 ,
.Xr csinh 3
.Sh STANDARDS
The
.Fn ctanh ,
.Fn ctanhf
and
.Fn ctanhl
functions conform to
.St -isoC-99 .