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)

how would I do this question

To determine the degenerate form or forms of the parabola that cannot be obtained from the intersection of a plane and a double napped cone, you will first need to understand the various forms of degenerate parabolas and their characteristics.

Degenerate parabolas are special cases where the parabola loses some of its defining features. There are three main forms of degenerate parabolas:

1. The Point: In this form, the parabola reduces to a single point. A single point can be obtained when the plane is parallel to the axis of the double napped cone, and it intersects the vertex of the cone.

2. The Line: In this form, the parabola degenerates into a straight line. A line can be obtained when the plane is parallel to the symmetry axis of the cone and intersects the double napped cone's directrix.

3. The Double Line: In this form, the parabola degenerates into two parallel lines. This occurs when the plane is parallel to the axis of the double napped cone but does not intersect the vertex. It intersects the two halves of the double cone, resulting in two parallel lines.

To determine the forms of degenerate parabolas that cannot be obtained from the intersection of a plane and a double napped cone, start by drawing a diagram of the double napped cone on a coordinate plane. Label the vertex, the axis, and the directrix.

Next, draw lines representing the various planes parallel to the axis and symmetry axis of the cone. Determine the intersections between these planes and the cone.

By analyzing the intersections, you can identify which forms of degenerate parabolas are obtained. Any other form of degenerate parabola apart from the three mentioned above would be considered as the answer to your question.

Make sure to label and describe each form of degenerate parabola accurately in your diagram and explanation to provide a complete description of how to obtain these forms.