JEE Main 2020MathematicsDifferentiationMediumMCQ

JEE Main 2020 — Differentiation Question with Solution

JEE Main 2020 (04 Sep Shift 1)

Question

If a+2bcosx)(a-2bcosy=a2-b2, where a>b>0, thendxdy at π4,π4 is:

Choose an option

Show full solutionCorrect option: C
Correct answer
Ca+ba-b

Step-by-step explanation

a+2bcosxa−2bcosy=a2−b2

a−2bcosy−2bsinxdxdy+2bsinya+2bcosx=0

dxdy=2bsinya+2bcosx2bsinxa−2bcosy=sinya+2bcosxsinxa−2bcosy

dxdyπ4,π4=a+ba−b.

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About this question

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