JEE Main 2018MathematicsDeterminantsMediumMCQ

JEE Main 2018 — Determinants Question with Solution

JEE Main 2018 (08 Apr)

Question

If x-42x2x2xx-42x2x2xx-4=A+Bx x-A2, then the ordered pair (A, B) is equal to

Choose an option

Show full solutionCorrect option: D
Correct answer
D-4, 5

Step-by-step explanation

x-42x2x2xx-42x2x2xx-4=A+Bx x-A2

Put x=0⇒-4000-4000-4=A3⇒A=-4

x-42x2x2xx-42x2x2xx-4=Bx-4x+42

1-4x2221-4x2221-4x=B-4x1+4x2

Put x→∞⇒122212221=B

On expanding the determinant along the first row, we get B=5.

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About this question

This is a previous-year question from JEE Main 2018, covering the Determinants 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.