How to change the size of Text area box , i want to increase the box size

I have been trying to figure out a good way to work with z-transform expressions which display keeping everything in terms of negative powers of z. I am not using the z-transform procedure, but writing the equations directly by hand.

For example, given an expression a*z^(-1), Maple will output this as a/z. This is even more dramatic when dealing with rational forms in z^(-1).

The issue here is that z^(-1) has an explicit meaning in terms of delay blocks and causality.

If anyone has a nice way for Maple to return these in a pretty-printed fashion retaining the z^(-1) terms, that would be great. I still need to be able to manipulate the expressions algebraically.

I think this is also wrong ode type given by ode advisor. The following clearly can't be **_dAlembert** ode.

restart; ode:=diff(y(x),x)*tan(diff(y(x),x))+ln(cos(diff(y(x),x))) = y(x);

It does not even have an explicit **x **on its own, in the RHS. D'Alembert ode has the form