Find the equation of the hyperbola with vertices at (±6, 0) and foci at (±8, 0).
Given: Vertices at (±6, 0) and foci at (±8, 0)
Need to find: The equation of the hyperbola
Let, the equation of the parabola be:
$\frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=1$
Vertices of the parabola is at $(\pm 6,0)$
That means $\mathrm{a}=6$
The foci are given at $(\pm 8,0)$
That means, ae = 8, where e is the eccentricity.
$\Rightarrow 6 \mathrm{e}=8[$ As $\mathrm{a}=6]$
$\Rightarrow \mathrm{e}=\frac{8}{6}=\frac{4}{3}$
We know that, $e=\sqrt{1+\frac{b^{2}}{a^{2}}}$
Therefore,
$\Rightarrow \sqrt{1+\frac{b^{2}}{a^{2}}}=\frac{4}{3}$
$\Rightarrow 1+\frac{b^{2}}{a^{2}}=\frac{16}{9}$ [Squaring both sides]
$\Rightarrow \frac{b^{2}}{a^{2}}=\frac{16}{9}-1=\frac{7}{9}$
$\Rightarrow b^{2}=a^{2} \frac{7}{9}$
$\Rightarrow \mathrm{b}^{2}=36 \times \frac{7}{9}=4 \times 7=28[$ As $\mathrm{a}=6]$
So, the equation of the hyperbola is,
$\frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=1 \Rightarrow \frac{x^{2}}{36}-\frac{y^{2}}{28}=1$ [Answer]