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JEE MainMathematicsModerateDifferential equation

If y(x) is the solution of the differential equation
dtdx\frac{dt}{dx} = - 2 (y - 1), then
lim⁡x→∞\mspace2muy(x)\lim_{x \rightarrow \infty}\mspace{2mu} y(x) equal.

Show answer and solution
dydx\frac{dy}{dx} = - 2 x (y - 1)
dydx\frac{dy}{dx} + 2 xy = 2x
I.F. =
e∫2xdx=ex2e^{\int 2xdx} = e^{x^{2}}
Solution
⇒\Rightarrow y⋅ex2=∫2xex2dx+cy \cdot e^{x^{2}} = \int 2xe^{x^{2}}dx + c
y⋅ex2=ex2+cy \cdot e^{x^{2}} = e^{x^{2}} + c........(1)
Given y(0) = 1
⇒\Rightarrow 1. 1 = 1 + c ⇒\Rightarrow c = 0
∴\therefore y⋅ex2=ex2y \cdot e^{x^{2}} = e^{x^{2}}
∴\therefore
lim⁡x→∞\mspace2muy(x)=lim⁡x→∞\mspace2mu(1)=1\lim_{x \rightarrow \infty}\mspace{2mu} y(x) = \lim_{x \rightarrow \infty}\mspace{2mu}(1) = 1

Source: Grass-G / M-13 Mathematics Paper 4 Nov.docx

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