Skip to content
dronacharya.ai
← JEE Main 2026 · 4 Apr · Shift 2
MathematicsSingle correct+4 / -1Question 11 of 75

JEE Main 2026 · 4 Apr · Shift 2, Mathematics question 11

Let H:x2a2−y2b2=1H:\dfrac{x^2}{a^2}-\dfrac{y^2}{b^2}=1 be a hyperbola such that the distance between its foci is 6 and the distance between its directrices is 83\dfrac83. If the line x=αx=\alpha intersects the hyperbola H at the points A and B such that the area of the triangle AOB is 4154\sqrt{15}, where O is the origin, then α2\alpha^2 equals

Choose one option
Answer and worked solution

Official answer: B

Hyperbola. 2ae=62ae=6 and 2ae=83\frac{2a}e=\frac83 give a2=4a^2=4, e=32e=\frac32, b2=5b^2=5.

Chord at x=αx=\alpha. y=±52α2−4y=\pm\frac{\sqrt5}2\sqrt{\alpha^2-4}.

Area. Area=α⋅52α2−4=415\text{Area}=\alpha\cdot\frac{\sqrt5}2\sqrt{\alpha^2-4}=4\sqrt{15}, so α2(α2−4)=192\alpha^2(\alpha^2-4)=192 and α2=16\alpha^2=16.

(B)

Topics:Hyperbola