Mathematics · Parabola

JEE Main 2025 — 22 January, Morning Shift — Question 13

Let the parabola y=x2+px−3y = x^2 + px - 3 meet the coordinate axes at the points P,QP, Q and R.R. If the circle CC with centre at (−1,−1)(-1, -1) passes through the points P,QP, Q and RR then the area of △PQR\triangle PQR is:

  1. Option A:

    4

  2. Option B:

    6

    Correct
  3. Option C:

    7

  4. Option D:

    5

Answer: B

Step-by-step solution

y=x2+px−3y = x^2 + px - 3 Let P(α,0),Q(β,0),R(0,−3)\text{Let } P(\alpha, 0), Q(\beta, 0), R(0, -3)

Circle with centre (−1,−1) (-1, -1) is (x+1)2+(y+1)2=r2 (x+1)^2 + (y+1)^2 = r^2

Passes through (0,−3)(0, -3)

12+(−2)2=r21^2 + (-2)^2 = r^2 r2=5r^2 = 5

(x+1)2+(y+1)2=5(x+1)^{2}+(y+1)^{2}=5

Put y=0y=0

(x+1)2=5−1(x+1)^{2}=5-1

(x+1)2=4(\mathrm{x}+1)^{2}=4

x+1=±2\mathrm{x}+1= \pm 2

x=1\mathrm{x}=1 or x=−3\mathrm{x}=-3

∴P(1,0)\therefore \mathrm{P}(1,0) and Q(−3,0)\mathrm{Q}(-3,0)

Area of △PQR=12∣101−3010−31∣=6\triangle \mathrm{PQR}=\frac{1}{2}\left|\begin{array}{ccc}1 & 0 & 1\\ -3 & 0 & 1 \\0 & -3 & 1\end{array}\right|=6

Answer key and solution verified before publishing.

Practise Parabola

Start with this question, then two more from the same chapter — with a tutor that explains every step. Free.

Exam
JEE Main 2025
Subject
Mathematics
Chapter
Parabola
Topic
Shortest distance between a Parabola and a Point/Line/Curve