

   HHyyppeerrbboolliicc FFuunnccttiioonnss

        cosh(x)
        sinh(x)
        tanh(x)
        acosh(x)
        asinh(x)
        atanh(x)

   DDeessccrriippttiioonn::

        These functions give the obvious hyperbolic functions.
        They respectively compute the hyperbolic cosine, sine,
        tangent, arc-cosine, arc-sine, arc-tangent.

   SSeeee AAllssoo::

        `cos', `sin', `tan', `acos', `asin', `atan'.

