Re: Mathematica plaintext output

• To: mathgroup at smc.vnet.net
• Subject: [mg107395] Re: [mg107368] Mathematica plaintext output
• From: Patrick Scheibe <pscheibe at trm.uni-leipzig.de>
• Date: Thu, 11 Feb 2010 06:54:17 -0500 (EST)
• References: <201002111016.FAA27914@smc.vnet.net>

```Hi,

the output says "your eigenvalues are the 3rd, 2nd and 1st root of the
polynomial 12 + 12x - 12x^2 + x^3, which are not calculated
analytically".

Want numerical values?

Eigenvalues[{{1, 2, 3}, {2, 6, 4}, {3, 4, 5}}] // N

Cheers
Patrick

On Thu, 2010-02-11 at 05:16 -0500, nevjernik wrote:
> Maybe this is trivial one, but I don't know how to interpret output of
> following:
>
> In:
> Eigenvalues[{{1, 2, 3}, {2, 6, 4}, {3, 4, 5}}]
>
> Out:
> {Root[12 + 12 #1 - 12 #1^2 + #1^3 &, 3],
>  Root[12 + 12 #1 - 12 #1^2 + #1^3 &, 2],
>  Root[12 + 12 #1 - 12 #1^2 + #1^3 &, 1]}
>
>
>
> WolframAlpha gives reasonable solutions:
>
> lambda_1 = 4+(6 2^(2/3))/(17+i sqrt(143))^(1/3)+(2 (17+i
> sqrt(143)))^(1/3)
> lambda_2 = 4-(3 2^(2/3) (1-i sqrt(3)))/(17+i sqrt(143))^(1/3)-((1+i
> sqrt(3)) (17+i sqrt(143))^(1/3))/2^(2/3)
> lambda_3 = 4-(3 2^(2/3) (1+i sqrt(3)))/(17+i sqrt(143))^(1/3)-((1-i
> sqrt(3)) (17+i sqrt(143))^(1/3))/2^(2/3)
>
>
> And below that, there is "mathematica plaintext output":
>
> {Root[12 + 12 #1 - 12 #1^2 + #1^3 & , 3, 0], Root[12 + 12 #1 - 12 #1^2
> + #1^3 & , 2, 0], Root[12 + 12 #1 - 12 #1^2 + #1^3 & , 1, 0]}
>
>
> Ok, it is obviously some plaintext output of result, but how one can
> deal with it in mathematica?
>
> Thanks
>
> --
> ne vesele mene bez vas
> utakmice nedjeljom
>
>
>

```

• Prev by Date: hi, how can i accomplish this densityplot?
• Next by Date: Re: Re: Upright \[Micro] in AxesLabel
• Previous by thread: Mathematica plaintext output
• Next by thread: Re: Mathematica plaintext output