Mathematics · Circles

JEE Main 2026 — 6 April, Evening Shift — Question 42

Let the line x−y=4x-y=4 intersect the circle C:(x−4)2+(y+3)2=9C: (x-4)²+(y+3)²=9 at the points QQ and R.R. If P(α,β)P(α,β) is a point on CC such that PQ=PR,PQ=PR, then (6α+8β)2(6α+8β)² is equal to ______.

Answer: 18

Numerical answer — enter this value.

Step-by-step solution

x−y=4x-y=4

(x-4)^{2}+(y+3)^{2}=9 \end{gathered}$$ $(\alpha, \beta)$ lies on circle $$\begin{gathered} \therefore(\alpha-4)^{2}+(\beta+3)^{2}=9 \end{gathered}$$ eq. (1) \& (2) $\Rightarrow y^{2}+(y+3)^{2}=9 \Rightarrow 2 y^{2}+6 y=0$ $\Rightarrow \mathrm{y}=0,-3$ $\therefore \mathrm{x}=4,1$ $\mathrm{Q}(4,0), \mathrm{R}(1,-3)$ now $(\mathrm{PQ})^{2}=(\mathrm{PR})^{2}$ $\Rightarrow(\alpha-4)^{2}+\beta^{2}=(\alpha-1)^{2}+(\beta+3)^{2}$ $$\begin{gathered} \Rightarrow \alpha+\beta=1 \end{gathered}$$ eq. (3) \& (4) $\Rightarrow \alpha=4+\frac{3}{\sqrt{2}}, \beta=-3-\frac{3}{\sqrt{2}}$ $\therefore(6 \alpha+8 \beta)^{2}=18$

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Mathematics
Chapter
Circles
Topic
Considering a Line or a Point wrt a Circle
Let the line x-y=4 intersect the circle C: (x-4)²+(y+3)²=9 at the… | JEE Main 2026 PYQ with Solution · DhiX AI