Calculating exact roots of 6th degree polynomial

I've a fat 6x6 matrix E with symbolic variables. I'm trying to compute sqrt(eig(E'E)), ie, the singular values. The answer begins with 'root( ) etc. How do I get MATLAB to solve this 6th degree polynomial and show me more pleasing answers? Thanks a lot.

Answer 1

[Image Analyst]

Use roots(), not root().

[Deepayan Bhadra]

It's being displayed as roots(....) in the MATLAB answer. It's not part of my command

[Walter Roberson]

root() is the placeholder that replaced RootOf() a couple of releases ago in the Symbolic Toolbox.

[Walter Roberson]

Which Galois group does it belong to? Because it is not generally possible to solve for exact algebraic roots.

https://en.wikipedia.org/wiki/Sextic_equation

By the way, have you ever looked at how long the roots are just for quartics? About 12500 characters per solution when using bare symbols for the coefficients; much much longer if the coefficients are expressions as you imply is happening for you.

Suppose you managed to find a (say) million character closed form for one of your eigenvalues: realistically, what would you do with it?