Re: Plot of (2 x^2 - x^3)^(1/3)
- To: mathgroup at smc.vnet.net
- Subject: [mg112082] Re: Plot of (2 x^2 - x^3)^(1/3)
- From: Matthias Bode <lvsaba at hotmail.com>
- Date: Sun, 29 Aug 2010 02:51:05 -0400 (EDT)
Please check
Table[{x, 2*x^2 - x^3, (2*x^2 - x^3)^
(1/3), Re[(2*x^2 - x^3)^(1/3)]},
{x, -4, 4}]
Best regards,
MATTHIAS BODE
S 17.35775=B0, W 066.14577=B0
> Date: Sat, 28 Aug 2010 07:01:34 -0400
> From: bernard.vuilleumier at edu.ge.ch
> Subject: [mg112057] Plot of (2 x^2 - x^3)^(1/3)
> To: mathgroup at smc.vnet.net
>
> I see in Calcul Diff==E9rentiel et int==E9gral, N. Piskounov, Editions
> MIR, Moscou 1970, on p. 210 the graph of (2 x^2 - x^3)^(1/3) with
> negative values for x > 2, something like :
>
> Plot[Piecewise[{{(2 x^2 - x^3)^(1/3), x <== 2}, {-Re[(2 x^2 -
> x^3)^(1/3)], x > 2}}], {x, -1, 3}]
>
> When I plot this function with :
>
> Plot[(2 x^2 - x^3)^(1/3) // Re, {x, -1, 3}]
>
> I obtain positives values for x > 3. I don't understand why.
> Thank you very much for your help !