JEE Main 2020MathematicsQuadratic EquationEasyMCQ

JEE Main 2020 — Quadratic Equation Question with Solution

JEE Main 2020 (03 Sep Shift 1)

Question

Consider the two sets:
A={m∈R: both the roots of x2-(m+1)x+m+4=0 are real } and B=[-3,5)
Which of the following is not true?

Choose an option

Show full solutionCorrect option: A
Correct answer
AA-B=(-∞,-3)∪(5,∞)

Step-by-step explanation

Since both roots are real m+12-4m+4≥0

⇒m2-2m-15≥0⇒m-5m+3≥0

⇒m∈(-∞,-3]∪[5,∞)

⇒A=(-∞,-3]∪[5,∞)

A-B=-∞,-3∪[5,∞) 

A∩B=-3

B-A=-3,5

A∪B=R

 

 

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About this question

This is a previous-year question from JEE Main 2020, 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.