Q210 / 270 · NDA 2016 (Phase 2) · Mathematics
What is the eccentricity of rectangular hyperbola?
- Correct answerA$\sqrt{2}$
- B$\sqrt{3}$
- C$\sqrt{5}$
- D$\sqrt{6}$
Solution
Here, $b^2=a^2\left(e^2-1\right)$
For rectangular hyperbola : $a=b$
$\begin{aligned}
& \Rightarrow b^2=b^2\left(e^2-1\right) \\
& \Rightarrow e^2-1=1 \\
& \Rightarrow e^2=2 \Rightarrow e= \pm \sqrt{2}
\end{aligned}$
For hyperbola, $\mathrm{e} \gt 1$.
Hence, $\mathrm{e}=\sqrt{2}$
Hence, the correct answer is option: 'A'.