Answer: less than 1.
- A less than 1
- B equal to 1
- C greater than 1
- D equal to 0
Correct answer: A. less than 1
Explanation: An ellipse always has eccentricity between 0 and 1.
All four conics form a single family distinguished only by eccentricity: a circle is the most "closed" (e=0), an ellipse is an elongated closed curve, a parabola is the borderline open curve (e=1), and a hyperbola has two separate open branches (e>1).
Concept context
Study circles, parabolas, ellipses, and hyperbolas as curves formed by intersecting a plane with a double cone, with their standard equations and key properties.