1 \(\frac{x^2}{9}-\frac{y^2}{16}=1\)
2 \(\frac{y^2}{9}-\frac{x^2}{16}=1\)
3 \(\frac{x^2}{9}-\frac{y^2}{25}=1\)
4 \(\frac{x^2}{25}-\frac{y^2}{9}=1\)
Explanation:
B Given,
\(\frac{x^2}{16}+\frac{y^2}{25}=1\)
Foci \((0, \pm\) be \()\)
\(\left[\because \quad \frac{\mathrm{x}^2}{\mathrm{a}^2}+\frac{\mathrm{y}^2}{\mathrm{~b}^2}=1\right]\)
\(a^2=16, b^2=25\)
\(a=4, b=5\)
Eccentricity,
\(\mathrm{e}_1^2 =1-\frac{\mathrm{a}^2}{\mathrm{~b}^2}\)
\(\mathrm{e}_1^2 =1-\frac{16}{25}\)
\(\mathrm{e}_1^2 =\frac{9}{25}\)
\(\mathrm{e}_1 =\frac{3}{5}\)
\(=(0, \pm \mathrm{be})\)
\(=\left(0, \pm \frac{3}{5} \times 5\right)\)
\(=(0, \pm 3)\)
\(\text { Foci }\)
\(\mathrm{e}_1 \times \mathrm{e}_2 =1\)
\(\mathrm{e}_2 =\frac{5}{3}\)
At, Hyperbola, \(\left(-\frac{x^2}{a^2}+\frac{y^2}{b^2}=1\right)\)
At, passes through \((0, \pm 3)\)
\((0,3)\) and \((0,-3)\)
\(=\left(\frac{0}{\mathrm{a}^2}+\frac{3^2}{\mathrm{~b}^2}=1\right)\)
\(\mathrm{b}^2=3^2, \mathrm{~b}=3\)
\(\mathrm{e}_2=\frac{5}{3}\)
\(\mathrm{e}_2^2=1+\frac{\mathrm{a}^2}{\mathrm{~b}^2}\)
\(\frac{25}{9}=1+\frac{\mathrm{a}^2}{9}\)
\(\frac{25}{9}=\frac{9+\mathrm{a}^2}{9}\)
\(\mathrm{a}^2=16\)
\(\mathrm{a}=4\)
In equation,
\(\frac{-x^2}{a^2}+\frac{y^2}{b^2}=1\)
\(\frac{-x^2}{16}+\frac{y^2}{9}=1\)
\(\frac{y^2}{9}-\frac{x^2}{16}=1\)