Feature request: cosh(asinh(x)) = sqrt(x^2+1)



On Jan 22, 2008 10:08 AM, Raymond Toy (RT/EUS) <raymond.toy at ericsson.com>
wrote:

> >> cosh(asinh(x)) = sqrt(x^2 + 1)
>


> Should maxima already know this and if so, how
> should it be done?  I think it would be easy to add this rule in
> trigo.lisp, but is that the right thing to do?
>

Sure, why not?  And the simplification should respect triginverses. I'm
assuming no one wants the written-out forms of asinh(cosh(x)),
atan(sinh(x)), etc. to be built-in, though.  They are rather messy and you
might as well use logarc/exponentialize.

              -s