Question

1. choose the best answer. an ellipse is the locus of points in a plane such that the sum of the distances from any point in the locus to two points, called the foci, is a __ directrix constant circular conic section

Explanation:

An ellipse is defined as the set of points in a plane where the sum of the distances from any point on the ellipse to two fixed points (the foci) is a constant value. A directrix is related to other conic sections (like parabolas) in a different way (involving a ratio with the focus). "Circular" refers to a circle (a special case of an ellipse but not the general property here). A conic section is the general category (ellipse is a type of conic section, but the blank is about the property related to the sum of distances to foci).

Answer:

B. constant