quick question!

kathy's

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Dec 20, 2005
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What degenerate form or forms of the parabola CANNOT be obtained from the intersection of a plane and a double napped cone?
I have to use a diagram and give complete description how to obtain this ( or these) form(s)

A degeneate is a the empty set (no intersection which seems impossible), a pairs of intersecting lines or a point. The way you get a pair of intersection lines is by passing a plane perpendicular to the cone base, but that is a type of hyperbola shape. So that point is the only thing you can get, by passing a plane parrallel with with the side of the cone through the vertex of the double cone.

My question is how would the diagrasm look like???
 
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