CONIC SECTIONS
Conic Sections These curves are known as conic sections or more commonly conics because they can be obtained as intersections of a plane with a double napped right circular cone. These curves have a very wide range of applications in fields such as planetary motions , design of telescopes and antennas , reflectors in flashlights and automobile headlights etc. Sections of a cone Let l be a fixed vertical line and m be another line intersecting it at a fixed point V and inclined to it at an angle α . Suppose we rotate the line m around the line l in such a way that the angle α remains constant. Then the surface generated is a double-napped right circular hollow cone herein after referred to as cone and extending indefinitely far in both directions. The point V is called the vertex ; the line l is the axis of the cone. The rotating line m is called the generator of the cone. The vertex separates the cone into two parts called nappes . I