Answer: (a, 0).
- A (a, 0)
- B (0, a)
- C (−a, 0)
- D (0, 0)
Correct answer: A. (a, 0)
Explanation: The focus of y² = 4ax is the point (a, 0).
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.