Re: Explicit solution to Root[]
- To: mathgroup at smc.vnet.net
- Subject: [mg58418] Re: Explicit solution to Root[]
- From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
- Date: Sat, 2 Jul 2005 04:06:14 -0400 (EDT)
- Organization: Uni Leipzig
- References: <da2mmv$932$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, a) RootReduce[] will simplify the expression a bit to Root[-24 + 6*#1 + 51*#1^2 - 40*#1^3 - 54*#1^4 + 54*#1^5 & , 1, 0] b) *this* is already a number, you can get a rational approximation or but this is the exact number. Regards Jens "Mukhtar Bekkali" <mbekkali at gmail.com> schrieb im Newsbeitrag news:da2mmv$932$1 at smc.vnet.net... > Here is the code: > > \!\(\(Root[\(-2\)\ #1\^3 + 2\ #1\^4 - #1\ > Root[\(-4\) - 3\ #1 + 66\ > #1\^2 + > 80\ #1\^3 - 108\ #1\^4 + 216\ #1\^5 &, > 1] - 6\ #1\^2\ > Root[\(-4\) - \ > 3\ #1 + 66\ #1\^2 + 80\ #1\^3 - 108\ #1\^4 + > 216\ #1\^5 &, > 1] + 6\ #1\^3\ Root[\(-4\) - > 3\ #1 + > 66\ #1\^2 + 80\ #1\^3 - 108\ #1\^4 + > 216\ #1\^5 &, 1] - 5\ \ > Root[\(-4\) - 3\ #1 + 66\ #1\^2 + 80\ #1\^3 - > 108\ #1\^4 + 216\ #1\^5 > &, \ > 1]\^2 - 6\ #1\ Root[\(-4\) - 3\ #1 + 66\ #1\^2 + > 80\ #1\^3 - 108\ #1\^4 > + > 216\ #1\^5 &, 1]\^2 + 6\ #1\^2\ > Root[\(-4\) - 3\ #1 + > 66\ #1\^2 + 80\ #1\^3 - 108\ > #1\^4 + 216\ #1\^5 &, > 1]\^2 - 2\ Root[\(-4\) - > 3\ #1 + 66\ #1\^2 + 80\ #1\^3 - > 108\ #1\^4 + 216\ #1\^5 > &, 1]\ > \^3 + 2\ #1\ Root[\(-4\) - 3\ #1 + 66\ #1\^2 + > 80\ #1\^3 - 108\ #1\^4 + > 216\ \ > #1\^5 &, 1]\^3 &, 2];\)\) > > I would guess it is a number. I applied > RootReduce, ToRadicals, N or > combinations of thereof, however, nothing seem > to convert the above > expression into an explicit number. What command > or sequence of > commands would do the job? Please advise. > Thanks, > > Mukhtar Bekkali >