Find the equation for the ellipse that satisfies the given conditions: Vertices (0, ±13), foci (0, ±5)
Question:
Find the equation for the ellipse that satisfies the given conditions: Vertices $(0, \pm 13)$, foci $(0, \pm 5)$
Solution:
Vertices $(0, \pm 13)$, foci $(0, \pm 5)$
Here, the vertices are on the y-axis.
Therefore, the equation of the ellipse will be of the form $\frac{x^{2}}{b^{2}}+\frac{y^{2}}{a^{2}}=1$, where $a$ is the semi-major axis.
Accordingly, a = 13 and c = 5.
It is known that $a^{2}=b^{2}+c^{2}$.
$\therefore 13^{2}=b^{2}+5^{2}$
$\Rightarrow 169=b^{2}+25$
$\Rightarrow b^{2}=169-25$
$\Rightarrow b=\sqrt{144}=12$
Thus, the equation of the ellipse is $\frac{x^{2}}{12^{2}}+\frac{y^{2}}{13^{2}}=1$ or $\frac{x^{2}}{144}+\frac{y^{2}}{169}=1$.