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If cot^-1(α )= cot^-12+ cot^-18+ cot^-118+ cot^-132+… . upto 100 terms, then α is:

JEE Main 2021 — Mathematics Trigonometry

2021mcqhard

If cot−1(α)=cot−12+cot−18+cot−118+cot−132+….{\mathrm{cot}}^{-1}(\alpha )={\mathrm{cot}}^{-1}2+{\mathrm{cot}}^{-1}8+{\mathrm{cot}}^{-1}18+{\mathrm{cot}}^{-1}32+\ldots .cot−1(α)=cot−12+cot−18+cot−118+cot−132+…. upto 100100100 terms, then α\alphaα is:

Official previous-year question

Held on 17 Mar 2021 · Verified 6 Jul 2026.

Options

  1. A

    1.011.011.01

  2. B

    1.001.001.00

  3. C

    1.021.021.02

  4. D

    1.031.031.03

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