Find the equation for the ellipse that satisfies the given conditions: Length of minor axis 16, foci (0, ±6)
Question:
Find the equation for the ellipse that satisfies the given conditions: Length of minor axis 16, foci (0, ±6)
Solution:
Length of minor axis = 16; foci = (0, ±6).
Since the foci are on the y-axis, the major axis is along 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, 2b = 16 ⇒ b = 8 and c = 6.
It is known that $a^{2}=b^{2}+c^{2}$.
$\therefore a^{2}=8^{2}+6^{2}=64+36=100$
$\Rightarrow a=\sqrt{100}=10$
Thus, the equation of the ellipse is $\frac{x^{2}}{8^{2}}+\frac{y^{2}}{10^{2}}=1$ or $\frac{x^{2}}{64}+\frac{y^{2}}{100}=1$.