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प्रतिबंधों को संतुष्ट करते हुए अतिपरवलय का समीकरण ज्ञात कीजिए
नाभियाँ $(0, \pm \sqrt{10})$, हैं तथा $(2,3)$ से होकर जाता है।
$\frac{y^{2}}{5}-\frac{x^{2}}{5}=1$
$\frac{y^{2}}{5}-\frac{x^{2}}{5}=1$
$\frac{y^{2}}{5}-\frac{x^{2}}{5}=1$
$\frac{y^{2}}{5}-\frac{x^{2}}{5}=1$
Solution
Foci $(0,\, \pm \sqrt{10}),$ passing through $(2,\,3)$
Here, the foci are on the $y-$ axis.
Therefore, the equation of the hyperbola is of the form $\frac{y^{2}}{a^{2}}-\frac{x^{2}}{b^{2}}=1$
since the foci are $(0,\,\pm \sqrt{10})$, $c=\sqrt{10}$
We know that $a^{2}+b^{2}=c^{2}$
$\therefore a^{2}+b^{2}=10$
$\Rightarrow b^{2}=10-a^{2}$ ……… $(1)$
since the hyperbola passes through point $(2,\,3)$
$\frac{9}{a^{2}}-\frac{4}{b^{2}}=1$ ……… $(2)$
From equations $(1)$ and $(2)$, we obtain
$\frac{9}{a^{2}}-\frac{4}{(10-a)^{2}}=1$
$\Rightarrow 9\left(10-a^{2}\right)-4 a^{2}=a^{2}\left(10-a^{2}\right)$
$\Rightarrow 90-9 a^{2}-4 a^{2}=10 a^{2}-a^{2}$
$\Rightarrow a^{2}-23 a^{2}+90=0$
$\Rightarrow a^{4}-18 a^{2}-5 a^{2}+90=0$
$\Rightarrow a^{2}\left(a^{2}-18\right)-5\left(a^{2}-18\right)=0$
$\Rightarrow\left(a^{2}-18\right)-\left(a^{2}-5\right)=0$
$\Rightarrow a^{2}=18$ or $5$
In hyperbola, $c > a,$ i.e., $c^{2} > a^{2}$
$\therefore a^{2}=5$
$\Rightarrow b^{2}=10-a^{2}=10-5=5$
Thus, the equation of the hyperbola is $\frac{y^{2}}{5}-\frac{x^{2}}{5}=1$