When a plane passes through the vertex of a double-napped cone, the intersection is a ________ ________.
A ________ is defined as the set of all points $(x, y)$ in a plane that are equidistant from a fixed line, called the ________, and a fixed point, called the ________, not on the line.
The ________ of a parabola is the midpoint between the focus and the directrix.
A line is ________ to a parabola at a point on the parabola if the line intersects, but does not cross, the parabola at the point.
In Exercises 9-12, describe in words how a plane could intersect with the double-napped cone shown to form the conic section.
Ellipse
Hyperbola