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AP EAMCET · Maths · Hyperbola

Let \(L L^{\prime}\) be the latus rectum through the focus \(S\) of a hyperbola and \(A^{\prime}\) be the opposite vertex of the hyperbola. If triangle \(A^{\prime} L L^{\prime}\) is equilateral, then the eccentricity of the hyperbola is

  1. A \(\frac{\sqrt{3}+1}{\sqrt{3}}\)
  2. B \(\frac{\sqrt{3}+1}{\sqrt{2}}\)
  3. C \(\frac{\sqrt{3}+1}{\sqrt{5}}\)
  4. D \(\sqrt{3}+1\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(\frac{\sqrt{3}+1}{\sqrt{3}}\)

Step-by-step Solution

Detailed explanation

Length of latus rectum \(LL' = \frac{2b^2}{a}\). Height of triangle \(A'LL'\) from \(A'(-a,0)\) to the line \(x=ae\) is \(h = ae - (-a) = a(e+1)\). For an equilateral triangle, \(h = \frac{\sqrt{3}}{2} \cdot LL'\). \(a(e+1) = \frac{\sqrt{3}}{2} \cdot \frac{2b^2}{a}\)…