On Fri, 6 Aug 2010, Bastiaan Bergman wrote:
> Exactly! And that "re-arranging by hand" I would like to have some tips for,
> or preferably some handy CAS routines.
It's hard to be sure without knowing what your functions f1, f2, f3,
and f4 are, but I think you'll probably find the following identities
useful:
cosh(z) = (1/2)*exp(z)*(1+exp(-2*z))
sinh(z) = (1/2)*exp(z)*(1-exp(-2*z))
In Maxima, exponentialize() followed by radcan() applies the
closely-related (i.e. by a straightforward change of variables)
identities
cosh(y) = (1/2)*exp(-y)*(exp(2*y)+1)
sinh(y) = (1/2)*exp(-y)*(exp(2*y)-1)
--
HTH,
Dan