1.\" $OpenBSD: ctanh.3,v 1.2 2013/06/05 03:40:26 tedu Exp $ 2.\" 3.\" Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: June 5 2013 $ 18.Dt CTANH 3 19.Os 20.Sh NAME 21.Nm ctanh , 22.Nm ctanhf , 23.Nm ctanhl 24.Nd complex hyperbolic tangent 25.Sh SYNOPSIS 26.In complex.h 27.Ft double complex 28.Fn ctanh "double complex z" 29.Ft float complex 30.Fn ctanhf "float complex z" 31.Ft long double complex 32.Fn ctanhl "long double complex z" 33.Sh DESCRIPTION 34The 35.Fn ctanh , 36.Fn ctanhf 37and 38.Fn ctanhl 39functions compute the complex hyperbolic tangent of 40.Fa z . 41.Pp 42If 43.Fa z 44= x + iy, then 45.Bd -literal -offset indent 46ctanh(z) = (sinh(2x) + i sin(2y)) / (cosh(2x) + cos(2y)). 47.Ed 48.Sh RETURN VALUES 49The 50.Fn ctanh , 51.Fn ctanhf 52and 53.Fn ctanhl 54functions return the complex hyperbolic tangent of 55.Fa z . 56.Sh SEE ALSO 57.Xr ccosh 3 , 58.Xr csinh 3 59.Sh STANDARDS 60The 61.Fn ctanh , 62.Fn ctanhf 63and 64.Fn ctanhl 65functions conform to 66.St -isoC-99 . 67