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Saturday, 31 October

JEE Main 2021 · MathsNumerical answerNumerical valueHardMulti-step

JEE Main 17 March 2021, Shift 1, Maths Q89

Question 89 of 90 in this shift, Maths question 29 of 30, Section B.

If f(x)=sin⁡(cos⁡−1(1−22x1+22x))f(x)=\sin\left(\cos^{-1}\left(\frac{1-2^{2x}}{1+2^{2x}}\right)\right) and its first derivative with respect to xx is −balog⁡e2-\frac{b}{a}\log_{e}2 when x=1x=1, where a and b are integers, then the minimum value of ∣a2−b2∣|a^{2}-b^{2}| is __________.

Official answer

481

NTA final key.

Same idea in other shifts

Asked 2× in all
  1. 2 Sep 2020, Shift 2 · Q72If y=∑k=16kcos⁡−1{35cos⁡kx−45sin⁡kx}y=\sum_{k=1}^{6} k\cos^{-1}\left\{\frac{3}{5}\cos kx-\frac{4}{5}\sin kx\right\}, then dydx\frac{dy}{dx} at x=0x=0 is ________.HardNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.