Conic curves (conics)
Curves formed by the intersection of a plane with a right circular cone. e.g. Parabola, hyperbola and ellipse. Right circular cone is a cone that has a circular base and the axis is inclined at 900 to  the base and passes through  the center of    the base.Conic sections are always "smooth". More precisely, they never contain any inflection points.  This is important for many applications, such as aerodynamics, civil engineering, mechanical engineering, etc.Figure 1. Shows a right cone and the various conic curves that can be obtained from a cone by sectioning the cone at various conditions.

 

Figure 1. Shows a right cone and the various conic curves that can be obtained from a cone by sectioning the cone at various conditions.