logo

Ask Questions, Get Answers

X
 
Home  >>  JEEMAIN and NEET  >>  Mathematics  >>  Class11  >>  Coordinate Geometry

The length of the major axis of the ellipse $\large\frac{x^2}{a^2}+\frac{y^2}{b^2}$$=1$ is 2 times the length of minor axis its eccentricity is :

$\begin{array}{1 1}(a)\;\large\frac{\sqrt 2}{3}\\(b)\;\large\frac{\sqrt 3}{2}\\(c)\;\large\frac{\sqrt 5}{3}\\(d)\;\text{None of these}\end{array}$

1 Answer

Length of major axis =2a
Length of minor axis =2b
We know
$b^2=a^2(1-e^2)$
$\big(\large\frac{b}{a}\big)^2$$=1-e^2$
$\big(\large\frac{1}{2}\big)^2$$=1-e^2$
$\large\frac{1}{4}$$-1=-e^2$
$e=\large\frac{\sqrt 3}{2}$
Hence (b) is the correct answer.
answered Feb 7, 2014 by sreemathi.v
edited Sep 23, 2014 by sharmaaparna1
 

Related questions

...