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For the given below, verify that the given function (implicit or explicit) is a solution to the corresponding differential equation. xy = a ex + b e-x + x2 : xd2ydx2+2dydx-xy+x2-2=0

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Question

For the given below, verify that the given function (implicit or explicit) is a solution to the corresponding differential equation.

xy = a ex + b e-x + x2 : `x (d^2y)/(dx^2) + 2 dy/dx - xy + x^2 - 2 = 0`

Sum
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Solution

Given function xy = a ex + b e-x + x

On differentiating with respect to x,

`dy/dx = ae^x - be^-x + 2x`

On differentiating again,

`(d^2y)/dx^2 = ae^x + be^-x + 2`

L.H.S. ⇒ `x (d^2y)/(dx^2) + 2 dy/dx - xy + x^2 - 2`

⇒ x(aex + be-x + 2) + 2(aex - be-x + 2x) - x(aex + be-x + x2) + x2 - 2

⇒ e(ax + 2a - ax) + e-x (bx - 2b - bx) + 2x + 4x - x3 + x2 - 2

`= 2ae^x - 2be^(- x) - x^3 + x^2 - 2 ne 0`

Hence, L.H.S. ≠ R.H.S.

Hence, the given function is not a solution of the differential equation.

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Chapter 9: Differential Equations - Exercise 9.7 [Page 420]

APPEARS IN

NCERT Mathematics Part 1 and 2 [English] Class 12
Chapter 9 Differential Equations
Exercise 9.7 | Q 2.1 | Page 420

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