Eccentricity (Mathematics)

The eccentricity of a conic section is a non-negative real number that uniquely characterizes its shape, serving as a measure of how far the conic deviates from being circular. A circle has eccentricity 0, a non-circular ellipse has eccentricity strictly between 0 and 1, a parabola has eccentricity exactly 1, a hyperbola has eccentricity greater than 1, and a degenerate conic consisting of a pair of lines has infinite eccentricity; two conic sections that share the same eccentricity are always similar to one another. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/