Another ellipse $E _2$ passing through the point $(0,4)$ circumscribes the rectangle $R$.. The eccentricity of the ellipse $E _2$ is
- A$\frac{\sqrt{2}}{2}$
- B$\frac{\sqrt{3}}{2}$
- ✓$\frac{1}{2}$
- D$\frac{3}{4}$
Another ellipse $E _2$ passing through the point $(0,4)$ circumscribes the rectangle $R$.. The eccentricity of the ellipse $E _2$ is
$E_2: \frac{x^2}{a^2}+\frac{y^2}{b^2}=1$
It passes thorugh $(0,4)$
$0+\frac{16}{b^2}=1 \quad \Rightarrow \quad b^2=16$
It also passes through $( \pm 3, \pm 2)$
$\frac{9}{a^2}+\frac{4}{b^2}=1 $
$\frac{9}{a^2}+\frac{1}{4}=1 $
$\frac{9}{a^2}=\frac{3}{4} \quad \Rightarrow \quad a^2=b^2\left(1-e^2\right) $
$\frac{12}{16}=1-e^2 $
$e^2=1-\frac{12}{16}=\frac{4}{16}=\frac{1}{4} $
$e=\frac{1}{2}$
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($A$) $Q_2 Q_3=12$
($B$) $ R_2 R_3=4 \sqrt{6}$
($C$) area of the triangle $O R_2 R_3$ is $6 \sqrt{2}$
($D$) area of the triangle $P Q_2 Q_3$ is $4 \sqrt{2}$