Differential equations

  • Thread starter sara_87
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  • #1
sara_87
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Homework Statement



i want to find the solution to:
dv/dx + 1/200 = 32/v

Homework Equations





The Attempt at a Solution



I don't know how to begin. what would be my first step?
 

Answers and Replies

  • #2
Hootenanny
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Can you identify which type of ODE it is? I.e. homogeneous/inhomogeneous, linear/non-linear etc.
 
  • #3
sara_87
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first order, linear
isn't it?
 
  • #4
Hootenanny
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first order, linear
isn't it?
It is indeed, so which method does one usually use for solving first order, linear ODE's?
 
  • #5
sara_87
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do multiply everything by v? or can we use the coefficient of v^(-1) to find the integrating factor?
 
  • #6
Hootenanny
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do multiply everything by v?
I would multiply it be v first, which puts the ODE into canonical form, and then find the IF.
 
  • #7
sara_87
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are we allowed to have v*(dv/dx)?
because when i did i got:

[ve^(x/200)]dv/dx + (v/200)e^(x/200) = 32e^(x/200)

i don't think that's right
 
  • #8
Hootenanny
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Ohh dear, was I am thinking?! The ODE is separable, try writing the ODE in the form,

[tex]\frac{dv}{dx}=f(v)[/tex]

Sorry about that, I had a stupid moment :uhh:
 
  • #9
sara_87
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its ok i always have stupid moments.
Thank you very much u've been much help.
 

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