Question

The minor axis of the ellipse $9x^2+5y^2=30y$ is

• A. $6$
• B. $2\sqrt{5}$
• C. $\sqrt{6}$
• D. $2\sqrt{6}$

Answer 1

The correct option is B $2\sqrt{5}$

Given ellipse may be written as $9x^2+5(y-3{)}^2=45$
$\Rightarrow \frac{x^2}{5}+\frac{(y-3{)}^2}{9}=1$
$\Rightarrow a=\sqrt{5},b=3$
Since $a<b\Rightarrow a$ is minor axis
$\therefore$ Length of minor axis is $=2a=2\sqrt{5}$