- Exam
- JEE Main
- Year
- 2023
- Date
- 25 January
- Shift
- Morning Shift
- Subject
- Mathematics
- Chapter
- Differential Equations
JEE Main 2023 · 25 January · Morning Shift · Mathematics · Differential Equations
Let y = y (x) be the solution curve of the differential equation...
Options
- A\dfrac{{x}^{2}}{5 - 2{x}^{3}\left(2 + \log_{e}{x}^{3}\right)}
- B
- C
- D\dfrac{{x}^{2}}{7 - 3{x}^{3}\left(2 + \log_{e}{x}^{2}\right)}
Correct answer
A. \dfrac{{x}^{2}}{5 - 2{x}^{3}\left(2 + \log_{e}{x}^{3}\right)}
Step-by-step solution
Given differential equation can be rewritten as,
Let \left(- \dfrac{1}{{y}^{2}}\right) = t ⇒ \dfrac{2}{{y}^{3}}\dfrac{dy}{dx} = \dfrac{dt}{dx}∴ \dfrac{dt}{2dx} + \dfrac{t}{x} = \left(1 + \log_{e}x\right)⇒ \dfrac{dt}{dx} + \dfrac{2t}{x} = 2\left(1 + \log_{e}x\right) . . . . . . . . . . ( 1 )\dfrac{dy}{dx} + Py = Q{ye}^{∫ Pdx} = ∫ {Qe}^{∫ Pdx} + C ( WhereI . F . = {e}^{∫ Pdx} )= {e}^{∫ \dfrac{2}{x}dx} = {x}^{2}\dfrac{- {x}^{2}}{{y}^{2}} = \dfrac{2}{3}\left(\left(1 + \log_{e}x\right){x}^{3} - \dfrac{{x}^{3}}{3}\right) + C . . . . . . ( 2 )y ( 1 ) = 3⇒ \dfrac{1}{9} = - 2\left(\dfrac{1}{3} - \dfrac{1}{9}\right) + C∴ C = \dfrac{5}{9}\dfrac{{y}^{2}}{9} = \dfrac{{x}^{2}}{5 - 2{x}^{3}\left(2 + \log_{e}{x}^{3}\right)}$