What kind of differential equation is this

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Discussion Overview

The discussion revolves around the classification and solvability of a specific differential equation modeled to address a real-world problem. Participants explore whether the equation is linear and discuss potential methods for solving it, including analytical approaches.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant presents the equation and questions its classification, noting that Maple identifies it as linear, but they express confusion about this classification.
  • Another participant asserts that the equation is linear and suggests clearing denominators to facilitate solving it, providing a transformed version of the equation.
  • A different participant reiterates the equation's linearity, explaining that "linear" refers to the sought function S, indicating that there are no higher powers of S in the equation.
  • Another participant suggests a standard form for first-order linear ordinary differential equations (ODEs) and implies that the equation can be manipulated into this form.
  • One participant proposes that the equation resembles a rate equation related to fluid dynamics, suggesting that it can be solved using separable equations.

Areas of Agreement / Disagreement

There is no clear consensus on the classification of the differential equation, as participants express differing views on its linearity and solvability. Some participants agree on its linear nature, while others question the classification and propose different methods for solving it.

Contextual Notes

Participants reference the need to clear denominators and manipulate the equation into a standard form, but specific assumptions or steps required for these transformations are not fully detailed. The discussion also hints at dependencies on definitions of linearity and the context of the problem being modeled.

Who May Find This Useful

Individuals interested in differential equations, particularly in the context of real-world applications, as well as those exploring methods for solving first-order linear ODEs.

fishingspree2
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I am trying to solve a real-world problem, and I have modeled it with the following equation:
[tex]\frac{dS}{dt}-3\left (\frac{150-S}{100-t} \right )+\frac{2S}{100+t}=0[/tex]

What kind of differential equation is that? Is it solvable analytically ?
Maple tells me it is linear, but I don't see how...
 
Last edited:
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I forget what that is called, but it is linear and easily solved. Clear denominators
(t-100)(t+100)s'(t) = (t+500) s(t)-450 t-45000
solve
(t-100)(t+100) s'(t) = (t+500) s(t)
use that to solve the original
naturally terms like
(t-100)m(t+100)n
arise
 
Last edited:
fishingspree2 said:
I am trying to solve a real-world problem, and I have modeled it with the following equation:
[tex]\frac{dS}{dt}-3\left (\frac{150-S}{100-t} \right )+\frac{2S}{100+t}=0[/tex]

What kind of differential equation is that? Is it solvable analytically ?
Maple tells me it is linear, but I don't see how...

It is a first order linear ODE
Of course it is easy to solve it, thanks to classical method.
"Linear" means linear relatively to the sought function S (There is no S² nor other functions of S. There are only S and S' in the equation).
It doesn't mean linear relatively to the variable t.
 
Last edited:
Write: dS/dt + f(t)S = g(t).
 
fishingspree2 said:
I am trying to solve a real-world problem, and I have modeled it with the following equation:
[tex]\frac{dS}{dt}-3\left (\frac{150-S}{100-t} \right )+\frac{2S}{100+t}=0[/tex]

What kind of differential equation is that? Is it solvable analytically ?
Maple tells me it is linear, but I don't see how...

Looks like rate of equation that determines solution or volume of liquid into a tank and out. Again it is solvable via separable equations.
 

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