Answer: y2 = 4ax.
- A x2 = 4ay
- B y2 = 4ax
- C x2/a2 + y2/b2 = 1
- D x2/a2 - y2/b2 = 1
Correct answer: B. y2 = 4ax
Explanation: y2 = 4ax is the standard form of a parabola opening rightward with vertex at the origin and axis along the x-axis.
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.