JEE Main 2026 — Application of Derivatives Question with Solution
JEE Main 2026 (21 January Shift 1)
Question
Let be a twice differentiable function such that the quadratic equation in m, has two equal roots for every . If , and is the largest interval in which the function is increasing, then is equal to .
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Correct answer
1
Step-by-step explanation
For equal roots in , discriminant = 0:
This gives
Integrating: , so
Using and : ,
For :
when , i.e.,
This gives
Integrating: , so
Using and : ,
For :
when , i.e.,
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This is a previous-year question from JEE Main 2026, covering the Application of Derivatives 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.