Exact 3rd degree poly root

[parisse]

Yes, but I think you did not understand what I wrote. It's nice to impress your friends with the root expressions with nested radicals, but after that you won't be able to simplify expressions easily. For example, it will probably be costly to find the value of the product of the three roots.
And by the way, there is an experimental version of Xcas that runs on your phone or tablet or any browser (Firefox recommended) Xcas online offline. Once downloaded, all computations are done on your phone, tablet or PC, you don't need an Internet connection anymore.