function y = acosh(z)
%ACOSH  Inverse hyperbolic cosine.
%   ACOSH(X) is the inverse hyperbolic cosine of the elements of X.

%   Copyright 1984-2000 The MathWorks, Inc. 
%   $Revision: 5.6 $  $Date: 2000/06/01 00:40:13 $
%   Built-in function.
