Polar Equations of Conics Can Be Used to Describe the Motion

Polar equations of conics can be used to describe the motion of comets. These paths can be graphed using the following polar equation, where e is the eccentricity of the conic and r _per is the perihelion distance measured in AU. For Encke's Comet r _per = 0.3317 and e = 0.8499, determine whether its trajectory is elliptical, parabolic, or hyperbolic. $r = \frac { r _ { \mathrm { per } } ( 1 + e ) } { 1 - e \cos \theta }$

A) parabolic
B) elliptical
C) hyperbolic