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Defining the program "Conic[f]".

This is a test to check if a given f is a Conic in x, y. We have to check if f is a degree 2 polynomial in x, y.

In[44]:=

$SubsetQ[L_, M_] := Complement[L, M] == {} ; (* X = Complement[L, M] is the list of element of L which are not in M . L is included in M if and only if X is empty *)$

$General :: spell1 : Possible spelling error: new symbol name \"SubsetQ\" is similar to existing symbol \"Subset\". More…$

In[45]:=

$ConicQ[f_] := And[ PolynomialQ[f], SubsetQ[Vari ... = {0, 0, 0}, Coefficient[f, {x^2 y, x^2 y^2, x y^2}] == {0, 0, 0}] ;$

We are now ready to introduce the program "Conic[f]".

In[46]:=

$RowBox[{ , RowBox[{Conic[f_], :=, RowBox[{Block, [, , &nbs ... dColor}, {CanonicalColor}},  ImageSize->400]}]}], , , ]}]}]}]$

$General :: spell1 : Possible spelling error: new symbol name \"Conic\" is similar to existing symbol \"ConicQ\". More…$

In[47]:=

(* NOTES ImplicitPlot fails to plot y^2 = 0 or equations involving only x . *)

Created by Mathematica (August 4, 2004)