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JEE Mains · Maths · STD 11 - 10.2 parabola,ellipse,hyperbola

Let the sum of the focal distances of the point \(\mathrm{P}(4,3)\) on the hyperbola \(\mathrm{H}: \frac{\mathrm{x}^2}{\mathrm{a}^2}-\frac{\mathrm{y}^2}{\mathrm{~b}^2}=1\) be \(8 \sqrt{\frac{5}{3}}\). If for \(H\), the length of the latus rectum is \(l\) and the product of the focal distances of the point P is m , then \(9 l^2+6 \mathrm{~m}\) is equal to :-

  1. A \(184\)
  2. B \(186\)
  3. C \(185\)
  4. D \(187\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(185\)

Step-by-step Solution

Detailed explanation

\(\begin{aligned} & e x+a+e x-a=8 \sqrt{\frac{5}{3}} \\ & 2 e x=8 \sqrt{\frac{5}{3}} \\ & 2 e \times 4=8 \sqrt{\frac{5}{3}} \\ & e=\sqrt{\frac{5}{3}} \\ & b^2=a^2\left(\left(\frac{\sqrt{5}}{3}\right)^2-1\right) \\ & b^2=\frac{2}{3} a^2\end{aligned}\)…