JEE Main 2021 · MathsMultiple choiceSingle correctEasyCalculation

JEE Main 18 March 2021, Shift 2, Maths Q75

Question 75 of 90 in this shift, Maths question 15 of 30, Section A.

Let the system of linear equations

4x+\lambda y+2z=0

2x-y+z=0

\mu x+2y+3z=0

\lambda, \mu\in\mathbb{R}

. has a non-trivial solution. Then which of the following is true ?

(1) $\lambda=3,\ \mu\in\mathbb{R}$
(2) $\mu=-6,\ \lambda\in\mathbb{R}$
(3) $\lambda=2,\ \mu\in\mathbb{R}$
(4) $\mu=6,\ \lambda\in\mathbb{R}$ Official answer

Official answer

Option 4

NTA final key.

Chapter: Determinants
Topic: Cramer's Rule
Idea tested: Parameter Evaluation in Homogeneous Systems

Same idea in other shifts

Asked 9× in all

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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.