Question

The latusrectum of the ellipse $9 x^2+16 y^2=144$, is

(a) 4

(b) $\frac{11}{4}$

(c) $\frac{7}{2}$

(d) $\frac{9}{2}$

Answer 1

SOLUTION — Given, $\frac{x^2}{16}+\frac{y^2}{9}=1$

Here, $a=4, b=3$

$\therefore$ Length of latusrectum

$=\frac{2 b^2}{a}=\frac{2 \times 9}{4}=\frac{9}{2}$

So, The correct option of this question will be (D).