.\"	$OpenBSD: casinh.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 CASINH 3
.Os
.Sh NAME
.Nm casinh ,
.Nm casinhf ,
.Nm casinhl
.Nd complex inverse hyperbolic sine
.Sh SYNOPSIS
.In complex.h
.Ft double complex
.Fn casinh "double complex z"
.Ft float complex
.Fn casinhf "float complex z"
.Ft long double complex
.Fn casinhl "long double complex z"
.Sh DESCRIPTION
The
.Fn casinh ,
.Fn casinhf
and
.Fn casinhl
functions compute the complex inverse hyperbolic sine of
.Fa z .
.Pp
For all complex floating-point numbers
.Fa z ,
.Bd -literal -offset indent
casinh(z) = -i casin(iz).
.Ed
.Sh RETURN VALUES
The
.Fn casinh ,
.Fn casinhf
and
.Fn casinhl
functions return the complex inverse hyperbolic sine of
.Fa z
with imaginary part in the interval
.Bq -Pi/2, Pi/2 ,
and unbounded real part.
.Sh SEE ALSO
.Xr cacosh 3 ,
.Xr catanh 3
.Sh STANDARDS
The
.Fn casinh ,
.Fn casinhf
and
.Fn casinhl
functions conform to
.St -isoC-99 .