https://math.stackexchange.com/questions/3436714/algorithm-to-find-common-tangent-to-any-two-conics
      を 味読 し      
https://www.yu-hanami.com/entry/2019/05/22/170200      
         倣い;
  -4 x^3+x^2 y^2+24 x^2-10 x y^2+y^4=0
が  可約曲線 reducible curve c1=0,c2=0
  を 示し common-tangent を 求めて
       図示をも 願います;
       
       
       なんども言うよ  ↑     
https://www.youtube.com/watch?v=Q9qAyt0G-jM