JEE Main 2020MathematicsApplication of DerivativesEasyMCQ

JEE Main 2020 — Application of Derivatives Question with Solution

JEE Main 2020 (03 Sep Shift 1)

Question

The function, fx=3x-7x23, x∈R, is increasing for all x lying in

Choose an option

Show full solutionCorrect option: A
Correct answer
A-∞,0∪1415,∞

Step-by-step explanation

fx=3x-7x23

For fx is increasing f'x>0.

Differentiate fx

f'x=3x23+3x-723x13

f'x=9x+23x-73x13

f'x=15x-143x13

Now f'x>0  ⇒15x-143x13>0

x∈-∞, 0∪1415, ∞

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About this question

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