Mathematics · Circles

JEE Main 2024 — 27 January, Shift 1 — Question 12

Four distinct points (2k,3k),(1,0),(0,1)(2 \mathrm{k}, 3 \mathrm{k}),(1,0),(0,1) and (0,0)(0,0) lie on a circle for kk equal to :

  1. Option A:

    213\frac{2}{13}

  2. Option B:

    313\frac{3}{13}

  3. Option C:

    513\frac{5}{13}

    Correct
  4. Option D:

    113\frac{1}{13}

Answer: C

Step-by-step solution

(2k,3k(2k, 3 k) will lie on circle whose diameter is AB

figure

(x−1)(x)+(y−1)(y)=0(x-1)(x)+(y-1)(y)=0 x2+y2−x−y=0x^{2}+y^{2}-x-y=0

Satisfy (2k,3k)(2 k, 3 k) in (i) (2k)2+(3k)2−2k−3k=0(2 \mathrm{k})^{2}+(3 \mathrm{k})^{2}-2 \mathrm{k}-3 \mathrm{k}=0

13k2−5k=013 \mathrm{k}^{2}-5 \mathrm{k}=0

k=0,k=513\mathrm{k}=0, \mathrm{k}=\frac{5}{13}

hence k=513\mathrm{k}=\frac{5}{13}

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Mathematics
Chapter
Circles
Topic
Introduction to Circles