Re: Cannot solve 3x3 Eigensystem

*To*: mathgroup at smc.vnet.net*Subject*: [mg68630] Re: Cannot solve 3x3 Eigensystem*From*: dimmechan at yahoo.com*Date*: Sun, 13 Aug 2006 05:52:52 -0400 (EDT)*References*: <ebhi7q$12a$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, kdittmer I can't understand what tou mean by "exact" solution. Your solution containing Root objects is exact. Anyway, you can use the Built in function ToRadicals. $Version 5.1 for Microsoft Windows (October 25, 2004) ??ToRadicals ToRadicals[expr] attempts to express all Root objects in expr in terms of radicals.More... Attributes[ToRadicals]={Protected} Options[ToRadicals]={Cubicsï?®True,Quarticsï?®True} However, what you get is a huge expression that I donâ??t know if it useful for you. BTW, while version 5.1 needs 0.375 sec. in my system to execute the command FullSimplify[Eigensystem[{{a1, b1, 0}, {b1, a2, b2}, {0, b2, a3}}, Cubics-> True], {b1, b2, a1, a2, a3} ï?? Reals] in version 5.2, I could not obtain the result of above command after 3 minutes so I give up. I guess something here. Any ideas? kdittmer wrote: > The result of > > FullSimplify[Eigensystem[{{a1, b1, 0}, {b1, a2, b2}, {0, b2, a3}}, > Cubics-> True], {b1, b2, a1, a2, a3} \[Element] Reals] > > is unfortunately containing Root[]. > > How do i get my exact solution?