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Suppose we have parametrized curve $\gamma(t)$. For instance, consider $\gamma(t)$ as the folium

folium[t_] := {3 t/(1 + t^3), 3 t^2/(1 + t^3)}

Then we obtained the Cartesian equation $f(x,y)=g(x,y)$ of $\gamma$ using Eliminate.

In our example

foliumimplicit := Eliminate[{x, y}==folium[t],t] 

gives us $x^3-3xy=-y^3$.

I would like to plot perturbations $f(x,y)=g(x,y)+\varepsilon$ of the implicit equation obtained. $x^3-3xy=-y^3+\varepsilon$ of the foliumimplicit equation obtained.

For our example, when $\varepsilon=0.1,-0.1$ the graphs of the $x^3-3xy=-y^3+\varepsilon$ are

enter image description here

enter image description here

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  • $\begingroup$ What is the question? Are you looking for ContourPlot? $\endgroup$ Commented Jul 7, 2019 at 14:03
  • $\begingroup$ My question was to try to create a program or function that has a parametrized curve as an input and give us the plots of perturbations of the cartesian equations of the curve (like in the example above of the folium). Hope now is clear my question. $\endgroup$
    – user66456
    Commented Jul 7, 2019 at 17:28

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One way to plot your curve is as a collection of contour plots with different values of e:

ContourPlot[Evaluate[Table[x^3 - 3 x y == e - y^3, {e, -0.1, 0.1, 0.05}]], 
            {x, -2, 2}, {y, -2, 2}]

enter image description here

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    $\begingroup$ Or simply draw several contours on the same graph: ContourPlot[x^3 - 3 x y + y^3, {x, -2, 2}, {y, -2, 2}, Contours -> Range[-0.1, 0.1, 0.05], ColorFunction -> (White &)] $\endgroup$
    – Roman
    Commented Jul 7, 2019 at 16:44

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