Conic Sections Question 528
Question: The equation of the parabola with (-3, 0) as focus and $ x+5=0 $ as directirx, is
[RPET 1985, 86, 89; MP PET 1991]
Options:
A) $ x^{2}=4(y+4) $
B) $ x^{2}=4(y-4) $
C) $ y^{2}=4(x+4) $
D) $ y^{2}=4(x-4) $
Show Answer
Answer:
Correct Answer: C
Solution:
Directrix $ =x+5=0 $
Focus is (-3, 0)
therefore $ 2a=(-5+3)=2 $
therefore $ a=1 $
Vertex is $ ( \frac{-3+(-5)}{2},0 )=(-4,0) $
Therefore, equation is $ {{(y-0)}^{2}}=4(x+4) $ .
BETA
