JEE Main 2021MathematicsStraight LinesMediumNumerical

JEE Main 2021 — Straight Lines Question with Solution

JEE Main 2021 (24 Feb Shift 2)

Question

Let a point P be such that its distance from the point 5,0 is thrice the distance of P from the point -5,0. If the locus of the point P is a circle of radius r, then 4r2 (in the nearest integer) is equal to __________.

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Show full solutionCorrect answer: 56
Correct answer
56

Step-by-step explanation

Let point is h,k

So, h-52+k2=3h+52+k2

8x2+8y2+100x+200=0

x2+y2+252x+25=0

r2=25242-25

4r2=2524-100

4r2=156.25-100

4r2=56.25

After round off 4r2=56

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About this question

This is a previous-year question from JEE Main 2021, covering the Straight Lines chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.