Conic Sections Question 365

Question: Eccentricity of the ellipse $ 9x^{2}+25y^{2}=225 $ is

[Kerala (Engg.) 2002]

Options:

A) $ \frac{3}{5} $

B) $ \frac{4}{5} $

C) $ \frac{9}{25} $

D) $ \frac{\sqrt{34}}{5} $

Show Answer

Answer:

Correct Answer: B

Solution:

The ellipse is $ \frac{x^{2}}{25}+\frac{y^{2}}{9}=1 $

$ \therefore e=\sqrt{1-\frac{b^{2}}{a^{2}}} $ i.e., $ \sqrt{1-\frac{9}{25}}=\frac{4}{5} $ .