Chapter 8: The Conic Sections
In this chapter, we study the Conic Sections - literally `sections of a cone'. Imagine a double-napped cone as seen below being `sliced' by a plane.

If we slice the cone with a horizontal plane the resulting curve is a circle.


Tilting the plane ever so slightly produces an ellipse.


If the plane cuts parallel to the cone, we get a parabola.


If we slice the cone with a vertical plane, we get a hyperbola.


If the slicing plane contains the vertex of the cone, we get the so-called `degenerate' conics: a point, a line, or two intersecting lines.
Adapted from Precalculus, Preliminary 4th Edition (integrated calculus), by Carl Stitz and Jeff Zeager (stitz-zeager.com), licensed under CC BY-NC-SA 3.0. Changes were made: reformatted as an accessible XYZ web edition. License: CC-BY-NC-SA-3.0.