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Solve the following differential equation. dr + (2r)dθ= 8dθ

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Question

Solve the following differential equation.

dr + (2r)dθ= 8dθ

Sum
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Solution

dr + (2r)dθ= 8dθ

`(dr)/(dθ)` + 2r = 8

The given equation is of the form

`(dr)/(dθ) + Pr = Q`

where, P = 2 and Q = 8

I.F. = `e ^(int^(P^dθ) = e^(int^(2^dθ) = e^(2θ)`

Solution of the given equation is

`r(I.F.) = int Q (I.F.) dθ + c`

`re^(2θ) = int 8 e^(2θ)  dθ + c`

`re^(2θ) = 8 int  e^(2θ)  dθ + c`

`re ^(2θ) = 8e^(2θ)/2 + c`

`re ^(2θ) = 4e^(2θ) + c`

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Chapter 8: Differential Equation and Applications - Exercise 8.5 [Page 168]

APPEARS IN

Balbharati Mathematics and Statistics 1 (Commerce) [English] Standard 12 Maharashtra State Board
Chapter 8 Differential Equation and Applications
Exercise 8.5 | Q 1.8 | Page 168

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