Conic Sections Question 364
Question: The foci of $ 16x^{2}+25y^{2}=400 $ are
[BIT Ranchi 1996]
Options:
A) $ (\pm 3,\ 0) $
B) $ (0,\ \pm 3) $
C) $ (3,\ -3) $
D) $ (-3,\ 3) $
Show Answer
Answer:
Correct Answer: A
Solution:
The equation of the ellipse is $ 16x^{2}+25y^{2}=400 $ or $ \frac{x^{2}}{25}+\frac{y^{2}}{16}=1 $ . Here $ a^{2}=25,b^{2}=16\Rightarrow e=\frac{3}{5} $ .
Hence the foci are $ (\pm 3,0). $
BETA
