JEE Main 2021MathematicsQuadratic EquationMediumMCQ

JEE Main 2021 — Quadratic Equation Question with Solution

JEE Main 2021 (25 Feb Shift 2)

Question

If α,β∈R are such that 1-2i (here i2=-1) is a root of z2+αz+β=0, then α-β is equal to:

Choose an option

Show full solutionCorrect option: A
Correct answer
A-7

Step-by-step explanation

∵α,β∈R⇒ other root is 1+2i

α=-( sum of roots )=-1-2i+1+2i=-2

β=product of roots =1-2i1+2i=5

∴α-β=-7

option 1

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About this question

This is a previous-year question from JEE Main 2021, covering the Quadratic Equation 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.