Conic Sections Question 388

Question: Eccentricity of the ellipse $ 4x^{2}+y^{2}-8x+2y+1=0 $ is

Options:

A) $ 1/\sqrt{3} $

B) $ \sqrt{3}/2 $

C) $ 1/2 $

D) None of these

Show Answer

Answer:

Correct Answer: B

Solution:

$ 4x^{2}-8x+y^{2}+2y+1=0 $

therefore $ {{(2x-2)}^{2}}+{{(y+1)}^{2}}=-1+4+1 $

therefore $ \frac{{{(x-1)}^{2}}}{1}+\frac{{{(y+1)}^{2}}}{4}=1 $

therefore $ e=\sqrt{1-\frac{1}{4}} $

therefore $ e=\frac{\sqrt{3}}{2} $ .