Re: Explicit solution to Root[]
- To: mathgroup at smc.vnet.net
- Subject: [mg58433] Re: [mg58407] Explicit solution to Root[]
- From: "David Park" <djmp at earthlink.net>
- Date: Sat, 2 Jul 2005 04:06:43 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Mukhtar, N worked for me with Version 5.1.1. expr = 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]; expr // N 1.11221 David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Mukhtar Bekkali [mailto:mbekkali at gmail.com] To: mathgroup 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