@Markiyan Hirnyk 

Yes, but the other actual real roots are ~  -1.99, 231., 357. and far away. 
I do not understand why the result is given in such a way (ok, may depend
on the algorithm).

@vv 

I *think* a good way is to look at the problem as one in symmetric function, as it was "sketched" in http://www.mapleprimes.com/posts/203207-Inequality-Proved-With-Maple-II#comment201358 by Christian Wolinski

Unfortunately he did not explain his code (it may be not the best idea to write answers through code only as compact as possible), I am lost in his last step.

But that would not answer your question about Maple asked here ...

There is something odd *in* this result, having the 3 forms RootOf(p, c) where
p:=405*z^12-249093*z^11+39961980*z^10-968381871*z^9+9198916991*z^8-42022051652*z^7
+119629825074*z^6-333034155032*z^5+409801359293*z^4+1724025966225*z^3
-4439614607910*z^2+646083771615*z-28968562521;

and c the constants 10.72743085, 8.672310704, 7.644750628 (using Digits=15).

The 1st one "is" a root, it is RootOf(p,z,index=1) while the two other ones
are no roots.

So how should one understand the result ?

@vv 

A question on the Cauchy estimates for |F(z)| <= M, which I can not see from
your first post: which M and circle do you take ... radius = a0?

That might be "done" numerically by the zero counting integral for h:= derivative of F, knowing that h vanishes of order 3 in z=0

PS: nice reduction to 1 variable

These infos are not enough, you may upload your Excel file.

I do not use it and have not installed the correct Excel version (using open office for such) - but there may be many reasons.

For example results, which Excel does not like. Or country settings. Or access rights ... BTW I could imagine that this operations can be done in Excel itself.

@acer 

This is really neat and it is worth a post of its own.

It should be said: this neat solution works for the standard interface.

Personally I use a pdf driver like pdfprinter - which always allows the choice between landscape or portrait (or multiple pages to one page), any application. For some free printers one has to take some care during installation, they may have doubtfull addtional features.

But it is so much more clear to enter a task like you have been told above. May be you should give it a try in future.

And Adri van de Meer already gave you a solution (without printing it).

Without data it is difficult to have a guess. You should try again, do not forget to insert the link to the file. If it really does not work then copy+paste as text.

It would be good if you provide the data (for example as text file or in a sheet).

And may be you also indicate what you expect and for what you roughly want to use the result.

well ... if you describe your steps and connads or better upload your try then ...

Actually: this is quite well documentated in the help. Have you used one of the examples and compared to your input?

That would also allow to handle number (or date) formats if settings for Excel are "European"

BTW a strange attitude in the linked forum to put such questions on 'hold'

Mine was y = x+ln(x), which seemed natural, solution is Wrightomega = LambertW@exp and luckily Maple succeeded. So it essentially is like Preben's approach.