acosh
=====

hyperbolic cosine inverse



Calling Sequence
~~~~~~~~~~~~~~~~


::

    [t]=acosh(x)




Arguments
~~~~~~~~~

:x real or complex vector or matrix.
: :t real or complex vector or matrix.
:



Description
~~~~~~~~~~~

The components of `t` are the inverse hyperbolic cosine of the
corresponding entries of `x`. Definition domain is ]1,+infinity[.



Sample
~~~~~~



Examples
~~~~~~~~


::

    x=[0,1,%i];
    `cosh`_(acosh(x))