JEE Main 2020MathematicsVector AlgebraMediumMCQ

JEE Main 2020 — Vector Algebra Question with Solution

JEE Main 2020 (08 Jan Shift 1)

Question

Let the volume of a parallelepiped whose coterminous edges are given by u→=i^+j^+λk^, v→=i^+j^+3k^ and w→=2i^+j^+k^ be 1 cu. unit. If θ be the angle between the edges u→ and w→, then the value of cos⁡θ can be

Choose an option

Show full solutionCorrect option: B
Correct answer
B763

Step-by-step explanation

±1=11λ113211 ⇒=-λ+3=±1⇒λ=2 or λ=4
For λ=4
cosθ=2+1+4618=763

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About this question

This is a previous-year question from JEE Main 2020, covering the Vector Algebra 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.