Question

1. choose the best answer.

a hyperbola is the locus of points in a plane such that the difference of the distances to two fixed points called the _ is a constant.
focus
parabola
foci
major axis

Explanation:

A hyperbola is defined as the set of all points in a plane such that the absolute value of the difference of the distances from two fixed points (called foci) is constant. The term "focus" is singular, and we need the plural form here. A parabola is a different conic section. The major axis is related to ellipses (and hyperbolas in a different context, but not as the fixed points).

Answer:

C. foci