JEE Main 2024MathematicsApplication of DerivativesEasyMCQ

JEE Main 2024Application of Derivatives Question with Solution

JEE Main 2024 (04 Apr Shift 2)

Question

Let be a real valued function. If and are respectively the minimum and the maximum values of , then is equal to

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Show full solutionCorrect option: A
Correct answer
A42

Step-by-step explanation

$\begin{aligned} & f(x)=3 \sqrt{x-2}+\sqrt{4-x} \\ & x-2 \geq 0 \& 4-x \geq 0 \\ & \therefore x \in[2,4] \end{aligned}x=2 \sin ^2 \theta+4 \cos ^2 \theta$ $\begin{aligned} & \therefore \mathrm{f}(\mathrm{x})=3 \sqrt{2}|\cos \theta|+\sqrt{2}|\sin \theta| \\ & \therefore \sqrt{2} \leq 3 \sqrt{2}|\cos \theta|+\sqrt{2}|\sin \theta| \leq \sqrt{9 \times 2+2} \\ & \sqrt{2} \leq 3 \sqrt{2}|\cos \theta|+\sqrt{2}|\sin \theta| \leq \sqrt{20} \\ & \therefore \alpha=\sqrt{2} \quad \beta=\sqrt{20} \\ & \alpha^2+2 \beta^2=2+40=42 \end{aligned}$

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About this question

This is a previous-year question from JEE Main 2024, 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.