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Saturday, 31 October

JEE Main 2021 · MathsNumerical answerNumerical valueHardMulti-step

JEE Main 18 March 2021, Shift 2, Maths Q86

Question 86 of 90 in this shift, Maths question 26 of 30, Section B.

Let y=y(x)y=y(x) be the solution of the differential equation x dy−y dx=(x2−y2) dxx\,dy-y\,dx=\sqrt{(x^2-y^2)}\,dx, x≥1x\ge1, with y(1)=0y(1)=0. If the area bounded by the line x=1x=1, x=eπx=e^{\pi}, y=0y=0 and y=y(x)y=y(x) is αe2π+β\alpha e^{2\pi}+\beta, then the value of 10(α+β)10(\alpha+\beta) is equal to ___________.

Official answer

4

NTA final key.

Same idea in other shifts

Asked 10× in all
  1. 5 Apr 2026, Shift 1 · Q25Let y=y(x)y = y(x) be the solution of the differential equation…HardNumerical value
  2. 9 Apr 2024, Shift 1 · Q10The solution of the differential equation (x2+y2)dx−5xy dy=0(x^2+y^2)dx-5xy\,dy=0, y(1)=0y(1)=0, is :MediumSingle correct
  3. 10 Apr 2023, Shift 1 · Q10The slope of tangent at any point (x,y)(x,y) on a curve y=y(x)y=y(x) is x2+y22xy\frac{x^2+y^2}{2xy}, x>0x>0. If y(2)=0y(2)=0, then a value of y(8)y(8) isMediumSingle correct
  4. 25 Jul 2022, Shift 2 · Q25Let y=y(x)y=y(x) be the solution of the differential equation dydx=4y3+2yx23xy2+x3, y(1)=1\frac{dy}{dx}=\frac{4y^3+2yx^2}{3xy^2+x^3},\ y(1)=1. If for some…MediumNumerical value
  5. 28 Jul 2022, Shift 1 · Q1Let the solution curve of the differential equation x dy=(x2+y2+y)dx, x>0x\,dy=\left(\sqrt{x^2+y^2}+y\right)dx,\ x>0, intersect the line x=1x=1 at y=0y=0 and…MediumSingle correct
  6. 28 Jun 2022, Shift 1 · Q10Let the solution curve y=y(x)y=y(x) of the differential equation…HardSingle correct
  7. 29 Jun 2022, Shift 1 · Q2Let the solution curve of the differential equation xdydx−y=y2+16x2x\frac{dy}{dx} - y = \sqrt{y^2 + 16x^2}, y(1)=3y(1) = 3 be y=y(x)y = y(x). Then y(2)y(2) is…MediumSingle correct
  8. 9 Jan 2020, Shift 2 · Q64If dydx=xyx2+y2\frac{dy}{dx}=\frac{xy}{x^2+y^2}; y(1)=1y(1)=1; then a value of xx satisfying y(x)=ey(x)=e is :MediumSingle 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 108 of the 174 JEE Main shifts held from 2017 to 2026.