Plot of (2 x^2 - x^3)^(1/3)
- To: mathgroup at smc.vnet.net
- Subject: [mg112057] Plot of (2 x^2 - x^3)^(1/3)
- From: Bernard <bernard.vuilleumier at edu.ge.ch>
- Date: Sat, 28 Aug 2010 07:01:34 -0400 (EDT)
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 !