JEE Main 2019MathematicsCircleTangent And NormalmediumMCQ

JEE Main 2019 — Circle Question with Solution

From: JEE Main 2019 (Online) 10th April Morning Slot

Question

The line x = y touches a circle at the point (1,1). If the circle also passes through the point (1, – 3), then its radius is :

Choose an option

Show full solutionCorrect option: C
Correct answer
C2

Step-by-step explanation

Equation of circle = (x – 1)2 + (y –1)2 + (y – x) = 0

Which passes through (1, –3)

JEE Main 2019 (Online) 10th April Morning Slot Mathematics - Circle Question 115 English Explanation

So, 0 + 16 + (–3 – 1) = 0

16 + (–4) = 0

= 4

Now equation of circle

(x – 1)2 + (y – 1)2 + 4y – 4x = 0

x2 + y2 – 6x + 2y + 2 = 0

radius =

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About this question

This is a previous-year question from JEE Main 2019, covering the Circle 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.