JEE Main 2016MathematicsCircleMediumMCQ

JEE Main 2016 — Circle Question with Solution

JEE Main 2016 (03 Apr)

Question

The centres of those circles which touch the circle, x2+y2-8x-8y-4=0, externally and also touch the x - axis, lie on

Choose an option

Show full solutionCorrect option: B
Correct answer
BA parabola

Step-by-step explanation

Given circle x2+y2-8x-8y-4=0

has centre 4, 4 and radius 6.

Let h, k be the centre of the circle which is touching the given circle externally



Then

h-42+k-42=6+k

⇒h2-8h+16+k2-8k+16=36+12k+k2

⇒h2-8h-20k-4=0 ,

Replacing h by x and k  by y, locus is

x2-8x-20y-4=0

Which is equation of parabola.

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About this question

This is a previous-year question from JEE Main 2016, 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.