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For the differential equation, find the general solution: (x+3y2)dydx=y(y>0) - Mathematics

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Question

For the differential equation, find the general solution:

`(x + 3y^2) dy/dx = y(y > 0)`

Sum

Solution

`(x + 3y^2) dy/dx = y`

or `y dx/dy = x + 3y^2`

`dx/dy - x/y = 3y`

A vertical differential equation of the form `dx/dy + Px = Q.`

Here `P = - 1/y, Q = 3y`

∴ `I.F. = e^(int P dx) = e^(- int 1/y dy) = e^(- log y) = 1/y`

Hence, the general solution of the differential equation

⇒ `x × I.F. = int Q xx I.F. dx + C`

⇒ `x xx 1/y = int 1/y (3y) dy + C`

⇒ `x/y = 3 int 1 dy + C`

⇒ `x/y = 3y + C`

⇒ x = 3y2 + Cy

Which is the required solution.

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Chapter 9: Differential Equations - Exercise 9.6 [Page 414]

APPEARS IN

NCERT Mathematics [English] Class 12
Chapter 9 Differential Equations
Exercise 9.6 | Q 12 | Page 414

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