JEE Main 2021MathematicsTrigonometric Ratios & IdentitiesMediumMCQ

JEE Main 2021 — Trigonometric Ratios & Identities Question with Solution

JEE Main 2021 (26 Aug Shift 2)

Question

A 10 inches long pencil AB with mid point C and a small eraser P are placed on the horizontal top of a table such that PC=5 inches and ∠PCB=tan-1(2). The acute angle through which the pencil must be rotated about C so that the perpendicular distance between eraser and pencil becomes exactly 1 inch is :

Choose an option

Show full solutionCorrect option: A
Correct answer
Atan-134

Step-by-step explanation

From figure,

sinβ=15tanβ=12
tan(α+β)=2tanα+β=tanα+121-tanα .12=2
α=tan-134

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About this question

This is a previous-year question from JEE Main 2021, covering the Trigonometric Ratios & Identities 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.