Question

The length of the double ordinate which is conjugate to the directrix of the ellipse $\frac{x^2}{25}+\frac{y^2}{16}=1$ is :

• A. $\frac{32}{3}$
• B. $\frac{32}{9}$
• C. $\frac{32}{25}$
• D. $\frac{32}{5}$

Answer 1

The correct option is D $\frac{32}{5}$

Given, equation of ellipse $\frac{x^2}{25}+\frac{y^2}{16}=1$
we know that length of the double ordinate which is conjugate to the directrix of the ellipse is given by $\frac{2b^2}{a}=\frac{32}{5}$.