I have
a:=-(diff(x(t), t))^2*h^2/(x(t)^2-2*d*x(t)+d^2+h^2)^(3/2);
                       

How do you collect the denominator to get

Never really used the writeto command but what's with all the typesetting gobbledygook in the text file?  It occurs with document and worksheet mode.  Perhaps it's only meant for classic or command line maple?

I think   looks much nicer than

it is indeed the answer to .  Both above are equal but there are less terms on the left.  It's just what Maple does - it doesn't like radicals in the denominator.  For just a little overhead I would prefer a collection of any sqrt value into the denominator than to have to split it up.  Maybe just my preference.  Perhaps an option could be available within the Maple system to allow numeric radicals in the denominator? 

The Maplecloud and maplesoft web pages only have the latest version of the physics package. 

Is there an archive of older physics packages?  ie. the latest versions to go with each of the older versions of Maple?

For example the elemetary charge e constant has the derive descriptor.  Having the descriptor in it, I might have thought there is a builtin way to pull out the derive equation there isn't so one has to do it this way

with(ScientificConstants):
rhs(GetConstant(e)[3])
                                    

However you wouldn't know the 3rd indexed position in the constant was the derive descriptor - it could be in a different location for another constant.

Also, what I wonder is, where is the derive for the Fine Structure Constant ?