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Friday, 9 October

JEE Main 2021 · MathsNumerical answerNumerical valueMediumMulti-step

JEE Main 25 July 2021, Shift 1, Maths Q85

Question 85 of 90 in this shift, Maths question 25 of 30, Section B.

Let y=y(x)y=y(x) be solution of the following differential equation eydydx−2eysin⁡x+sin⁡xcos⁡2x=0e^y\frac{dy}{dx}-2e^y\sin x+\sin x\cos^2x=0, y(π2)=0y\left(\frac{\pi}{2}\right)=0. If y(0)=log⁡e(α+βe−2)y(0)=\log_e(\alpha+\beta e^{-2}), then 4(α+β)4(\alpha+\beta) is equal to _________.

Official answer

4

NTA final key.

Same idea in other shifts

Asked 2× in all
  1. 4 Apr 2025, Shift 2 · Q20If a curve y=y(x)y=y(x) passes through the point (1,π2)\left(1,\frac{\pi}{2}\right) and satisfies the differential equation…HardSingle correct

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 42 of the 174 JEE Main shifts held from 2017 to 2026.