JEE Main 2020 — Parabola Question with Solution
From: JEE Main 2020 (Online) 5th September Morning Slot
Question
If the common tangent to the parabolas,
y2 = 4x and x2 = 4y also touches the circle, x2 + y2 = c2,
then c is equal to :
y2 = 4x and x2 = 4y also touches the circle, x2 + y2 = c2,
then c is equal to :
Choose an option
Show full solutionCorrect option: A
Correct answer
A
Step-by-step explanation
(tangent at y2
= 4x)
y = mx – m2 (tangent at x2 = 4y)
(for common tangent)
m3 = – 1
m = - 1
Equation of tangent
y = –x –1
x + y + 1 = 0
This line touches circle whose center at (0, 0),
apply p( Distance from center of the circle of the line ) = r ( Radius of the circle )
c =
y = mx – m2 (tangent at x2 = 4y)
(for common tangent)
m3 = – 1
m = - 1
Equation of tangent
y = –x –1
x + y + 1 = 0
This line touches circle whose center at (0, 0),
apply p( Distance from center of the circle of the line ) = r ( Radius of the circle )
c =
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This is a previous-year question from JEE Main 2020, covering the Parabola 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.