How Do You Solve an Initial Value Problem with Integration Steps?

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Homework Help Overview

The discussion revolves around solving an initial value problem involving a first-order linear differential equation of the form ty' + (t+1)y = t, with the initial condition y(LN 2) = 1. Participants are exploring the integration steps and the use of an integrating factor.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the calculation of the integrating factor and question the correctness of the original poster's steps. There is a focus on the integration process and the formulation of the left-hand side of the equation.

Discussion Status

Feedback has been provided regarding the integrating factor, with some participants suggesting corrections to the original poster's approach. There is acknowledgment of a viable direction in the discussion, particularly with the mention of the correct integrating factor.

Contextual Notes

Participants are working under the constraints of an initial value problem and are focused on the integration steps necessary to solve the differential equation. There is an emphasis on ensuring the left side of the equation aligns with the expected form for integration.

newtomath
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I need help with an initial value problem,

ty' + (t+1)y= t; y (LN 2)= 1

I divided t and have u(t) as exp Integral of t+1/1 => e^t +t

Multiplied this to the original equation to get

(e^t +t)y' + ((t+ 1)/t) *y *(e^t +t) = (e^t +t)

How can I integrate the above? Are my steps so far correct?

Thanks
 
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I divided t and have u(t) as exp Integral of t+1/1 => e^t +t
( e^t + t ) isn't correct !
 
Last edited:
newtomath said:
I need help with an initial value problem,

ty' + (t+1)y= t; y (LN 2)= 1

I divided t and have u(t) as exp Integral of t+1/1 => e^t +t

Multiplied this to the original equation to get

(e^t +t)y' + ((t+ 1)/t) *y *(e^t +t) = (e^t +t)

How can I integrate the above? Are my steps so far correct?

Thanks

So, you are trying to solve using linear method?
 
newtomath said:
I need help with an initial value problem,

ty' + (t+1)y= t; y (LN 2)= 1

I divided t and have u(t) as exp Integral of t+1/1 => e^t +t
You mean that, to find an integrating factor, you integrated (t+1)/t which is the same as 1+ 1/t. From that you get ln(u)= t+ ln(t), [itex]u= e^{t+ ln(t)}= e^t*e^{ln t}= te^t[/itex], NOT [itex]e^t+ t[/itex]

Multiplied this to the original equation to get

(e^t +t)y' + ((t+ 1)/t) *y *(e^t +t) = (e^t +t)
The whole point of the integrating factor is that the left side should be equal to
((e^t+ t)y)'- and it isn't!

How can I integrate the above? Are my steps so far correct?

Thanks
 
Thanks for all the feedback.

@halls- thanks, te^t did it for me, problem solved.
 

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