Conic-Sections Question 589
The sum of the focal distances of a point on the ellipse $ \frac{x^{2}}{4}+\frac{y^{2}}{9}=1 $ is:
Options:
A) 4 units
B) 6 units
C) 8 units
D) 10 units
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Given equation of ellipse is $ \frac{x^{2}}{4}+\frac{y^{2}}{9}=1 $
$ \Rightarrow \frac{x^{2}}{{{(2)}^{2}}}+\frac{y^{2}}{{{(3)}^{2}}}=1\Rightarrow a=3 $ and $ b=2 $ Length of major axis $ =2a=6 $ Since, we have Sum of the focal distance of a point on ellipse = length of major axis.
$ \therefore $ Required Ans = 4 units.
BETA
