If the latus rectum of a hyperbola through one focus subtends an angle \(60^{\circ}\) at the other focus,…

If the latus rectum of a hyperbola through one focus subtends an angle \(60^{\circ}\) at the other focus, then its eccentricity is
  1. \(\sqrt{2}\)
  2. \(\sqrt{6}\)
  3. \(\sqrt{3}\)
  4. \(\sqrt{5}\)

Solution

Given, latus rectum of one hyperbola subtends an angle of \(60^{\circ}\) at other follows,
From \(\triangle A B C\), \(\begin{array}{llll} & \tan 30^{\circ} =\frac{b^2 / a}{2 a e} \\ \Rightarrow & \frac{1}{\sqrt{3}} =\frac{b^2}{2 a^2 e} \\ & \text {Also } b^2 =a^2\left(e^2-1\right) \\ & \text {So, } \frac{1}{\sqrt{3}} =\frac{a^2\left(e^2-1\right)}{2 a^2 e} \\ \Rightarrow & 2 e =\sqrt{3}\left(e^2-1\right) \\ \Rightarrow & e =\sqrt{3} \end{array}\)

Asked in: AP EAMCET 2020 (17 Sep Shift 2)

Practice more Hyperbola questions on Aicharya