Mathematics · Hyperbola

JEE Main 2025 — 3 April, Evening Shift — Question 41

If the equation of the hyperbola with foci (4,2)(4,2) and (8,2)(8,2) is 3x2−y2−αx+βy+γ=03 x^{2}-y^{2}-\alpha x+\beta y+\gamma=0, then

α+β+γ\alpha+\beta+\gamma is equal to \qquad -.

Answer: 141

Numerical answer — enter this value.

Step-by-step solution

Given (x−6)2a2−(y−2)2b2=1\frac{(x-6)^{2}}{a^{2}}-\frac{(y-2)^{2}}{b^{2}}=1

⇒b2x2−a2y2−12xb2+4ya2+36b2−4a2−a2b2=0\Rightarrow b^{2} x^{2}-a^{2} y^{2}-12 x b^{2}+4 y a^{2}+36 b^{2}-4 a^{2}-a^{2} b^{2}=0 Comparing b2a2=3⇒e2=1+b2a2\frac{b^{2}}{a^{2}}=3 \Rightarrow e^{2}=1+\frac{b^{2}}{a^{2}}

⇒e2=4⇒e=2\begin{aligned} & \Rightarrow e^{2}=4 \\& \Rightarrow e=2 \end{aligned}

Similarly, 2ae=42 a e=4

⇒a=1⇒b=3\Rightarrow a=1 \Rightarrow b=\sqrt{3}

(x−6)21−(y−2)23=1\frac{(x-6)^{2}}{1}-\frac{(y-2)^{2}}{3}=1

⇒3x2−y2−36x+4y+108−4−3=0\Rightarrow 3 x^{2}-y^{2}-36 x+4 y+108-4-3=0

⇒3x2−y2−36x+4y+101=0\Rightarrow 3 x^{2}-y^{2}-36 x+4 y+101=0

⇒α=36,β=4,γ=101\Rightarrow \alpha=36, \beta=4, \gamma=101

⇒α+β+γ=141\Rightarrow \alpha+\beta+\gamma=141

Solution figure

Answer key and solution verified before publishing.

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Exam
JEE Main 2025
Subject
Mathematics
Chapter
Hyperbola
Topic
Introduction to Hyperbola