Chapter 11. Conic Section

Introduction: 

There are some curves like circles, ellipses, parabolas and hyperbolas, which obtains as intersections of a plane with a double napped right circular cone. These curves are known as conic sections. 

• The names parabola and hyperbola are given by Apollonius.
• We can obtain different type of curves by subsequent sections  in a plane of double napped right circular cone. 

Uses: 

These curves have a very wide range of applications in fields such as planetary motion, design of telescopes and antennas, reflectors in flashlights and automobile headlights, etc.                                        

Napped cone Fig. 11.1 

Vertex: The point where two napped cone join together. In fig. 11.1 the point V is called vertex. 

Generator: Roatating line m is called generator of the cone. 

The vertex separates the cone into two parts called nappes.

If we take the intersection of a plane with a cone, the section so obtained is called a conic section.

The section obtained by a intersection of cone with plane is known as conic section.