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Re: implcit plot with undefined expression

• To: mathgroup at smc.vnet.net
• Subject: [mg18844] Re: [mg18780] implcit plot with undefined expression
• From: Markus van Almsick <m.van.almsick at cityweb.de>
• Date: Thu, 22 Jul 1999 22:57:45 -0400
• Sender: owner-wri-mathgroup at wolfram.com

Dear zoominzero,

You have two other options to obtain an Implicit Plot:

1. ContourPlot

ContourPlot[Re[Sqrt[2*Sqrt[2X^2 - Y^2] - 2*Y + X^2]], {X, -2, 2}, {Y, -2, 2},
  PlotPoints -> 120, Contours -> {0}]

The result is determined numerically and is not very good due to the
infinite slope of Sqrt around 0.


2. symbolic Solve

(Works in this case. Why not use is it?!)

Solve[Sqrt[2*Sqrt[2X^2 - Y^2] - 2*Y + X^2] == 0, Y]

Plot[Evaluate[Y /. %], {X, -2, 2}]



Ciao,  Markus van Almsick