JEE Main 2021 — Circle Question with Solution
From: JEE Main 2021 (Online) 24th February Evening Shift
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 is equal to ________
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Show full solutionCorrect answer: 56
Correct answer
56
Step-by-step explanation
Let P(h, k)
Given
PA = 3PB
PA2 = 9PB2
(h 5)2 + k2 = 9[(h + 5)2 + k2]
8h2 + 8k2 + 100h + 200 = 0
Locus
After Round of 4r2 = 56
Given
PA = 3PB
PA2 = 9PB2
(h 5)2 + k2 = 9[(h + 5)2 + k2]
8h2 + 8k2 + 100h + 200 = 0
Locus
After Round of 4r2 = 56
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