Answer: (4, 8) and (4, -8).
- A (4, 8) and (4, -8)
- B (4, 4) and (4, -4)
- C (8, 4) and (8, -4)
- D (2, 8) and (2, -8)
Correct answer: A. (4, 8) and (4, -8)
Explanation: With a=4, parabola is y²=16x; focus at (a,0)=(4,0). At x=4: y²=16(4)=64, y=±8. Latus rectum endpoints are (4,8) and (4,−8), and its length=2(2a)=16. Ans: (4,8) and (4,−8).
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.