Conic Sections Question 285

Question: The distance between the foci of the ellipse $ 3x^{2}+4y^{2}=48 $ is

Options:

A) 2

B) 4

C) 6

D) 8

Show Answer

Answer:

Correct Answer: B

Solution:

$ \frac{x^{2}}{(48/3)}+\frac{y^{2}}{(48/4)}=1 $

$ a^{2}=16,\ b^{2}=12 $

therefore $ e=\sqrt{1-\frac{b^{2}}{a^{2}}}=\frac{1}{2} $

Distance is $ 2ae=2\cdot 4\cdot \frac{1}{2}=4 $ .