JEE Main 2021 · MathsMultiple choiceSingle correctEasyCalculation

JEE Main 25 July 2021, Shift 2, Maths Q77

Question 77 of 90 in this shift, Maths question 17 of 30, Section A.

Let the equation of the pair of lines,

y=px

and

y=qx

, can be written as

(y-px)(y-qx)=0

. Then the equation of the pair of the angle bisectors of the lines

x^2-4xy-5y^2=0

is :

(1) $x^2-3xy-y^2=0$
(2) $x^2+3xy-y^2=0$ Official answer
(3) $x^2-3xy+y^2=0$
(4) $x^2+4xy-y^2=0$

Official answer

Option 2

NTA final key.

Chapter: Straight Lines
Topic: Pair of Straight Lines
Idea tested: Equation of angle bisectors

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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.