Conic Sections Question 506
Question: Focus and directrix of the parabola $ x^{2}=-8ay $ are
[RPET 2001]
Options:
A) $ (0,\ -2a)\ and\ y=2a $
B) $ (0,\ 2a)\ and\ y=-2a $
C) $ (2a,\ 0)\ and\ x=-2a $
D) $ (-2a,\ 0)\ and\ x=2a $
Show Answer
Answer:
Correct Answer: A
Solution:
Given equation is $ x^{2}=-8ay. $ Here $ A=2a $
Focus of parabola $ (0,-A) $ i.e. (0, - 2a) Directrix y = A i.e., y = 2a.
BETA
