Answer: y² = 4ax.
- A y² = 4ax
- B x² = 4ay
- C x² + y² = a²
- D xy = a
Correct answer: A. y² = 4ax
Explanation: y² = 4ax opens rightward with vertex at the origin.
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.