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The length of the latus rectum and directrices of a hyperbola with eccentricity e are 9 and x \( = \pm \frac{4}{\sqrt{3}}\), respectively. Let the line \(\mathrm{y}-\sqrt{3} \mathrm{x}+\sqrt{3}=0\) touch this hyperbola at (x0, y0). If m is the product of the focal distances of the point (x0, y0), then 4e2 + m is equal to _______.

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Correct answer is: 61

\(\frac{2 \mathrm{~b}^2}{\mathrm{a}}=9 \text { and } \pm \frac{\mathrm{a}}{\mathrm{e}}= \pm \frac{4}{\sqrt{3}}\)           ....(1)

Equation of tangent \(y=\sqrt{3} x-\sqrt{3}\)

m = \(\sqrt3\)

c = \(-\sqrt3\)

Condition of tangency \(c= \pm \sqrt{a^2 m^2-b^2}\)

\(-\sqrt{3}=\sqrt{3 a^2-b^2}\)

\( 3=3 a^2-b^2\)

\( 6 a^2-9 a-6=0\)

\( 2 a^2-3 a-2=0\)

\( 2 a^2-4 a+a-2=0\)

\( (a-2)(2 a+1)=0\)

\( a=2 \text { or }-\frac{1}{2}\)

when \(\mathrm{a}=2, \mathrm{~b}^2=9\) put a = 2 in           ...(1)

\( \frac{2}{\mathrm{e}}=\frac{4}{\sqrt{3}} \Rightarrow \mathrm{e}=\frac{\sqrt{3}}{2}\)

Which is impossible

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