Assertion: parabola's focus | /r/HasProperty | divided by the distance
Facets:
value: to the vertex
type: OTHER
value: from the center
type: LOCATION
value: to the directrix
type: OTHER
Source sentences:
text: A conic is defined as the locus of points for each of which the distance to the focus divided by the distance to the directrix is a fixed positive constant, called the eccentricity e.
text: Any conic section can be described by a polar equation r = p / (1 + e cos θ), where e is the eccentricity, the ratio of the distance from the center to the focus divided by the distance from the center to the vertex, usually expressed as e = c/a, as in the case of an ellipse with semiaxes a and b and c = √(a2 + b2).