When I try this
ContourPlot[e (-208 Sqrt[1 - e^2] - 205 Sqrt[4 - e^2] +
2 e^2 (Sqrt[1 - e^2] + Sqrt[4 - e^2])) + 400 Sin[\[Phi]]== 0, {\[Phi],
0, 2*\[Pi]}, {e, -1, 1}]
It works and give nice plot but when I square the equation
ContourPlot[(e (-208 Sqrt[1 - e^2] - 205 Sqrt[4 - e^2] +
2 e^2 (Sqrt[1 - e^2] + Sqrt[4 - e^2])) + 400 Sin[\[Phi]])^2== 0, {\[Phi],
0, 2*\[Pi]}, {e, -1, 1}]
Nothing comes out; same thing happens if I take Abs[]
. I don't understand why these two are not equivalent to each other. Since usually I deal with complex equations, I need let the norm equal to zero, thus either square or Abs comes out. Is there a way to let the latter one works? Thanks
f
being your function:sols = Solve[f[\[Phi], e]^2 == 0, {e}]; ParametricPlot[Evaluate[{\[Phi], e} /. sols], {\[Phi], 0, 2 Pi}]
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