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Differential equations

Anonymous Fri 24 Jan 23:11:08 2020 No.11328525 View Reply Original Report

Quoted By: >>11328535 >>11328560 >>11329379

Can someone who is actually smart help me with this. I found the general solution as y = (5/14)x^(2/3)+cx^(2/3), but I have no idea what to do with the initial condition

Anonymous

Anonymous Fri 24 Jan 2020 23:14:45 No.11328535 Report

Quoted By: >>11328560 >>11328563

>>11328525
it tells you right there, y(1) = C, plug 1 into your general solution, set it equal to C, and solve.

Anonymous

Anonymous Fri 24 Jan 2020 23:21:17 No.11328560 Report

Quoted By: >>11328571

>>11328525
>>11328535
Yeahhhhh............
Your'e gonna wanna stop reusing that 'c' variable you put in there. You might have a bit of "problems," if you know what I mean...

Anonymous

Anonymous Fri 24 Jan 2020 23:21:53 No.11328563 Report

Quoted By:

>>11328535
Nah, I did that and it gives me that 5/14 + c = c, which isn't right.

Anonymous

Anonymous Fri 24 Jan 2020 23:23:41 No.11328571 Report

Quoted By: >>11328577

>>11328560
So, I use a different variable "D" for the general solution and then what?

Anonymous

Anonymous Fri 24 Jan 2020 23:27:05 No.11328577 Report

Quoted By: >>11328616

>>11328571
You plug in for y=D and x=1. Solve for the constant of integration, and plug that back into the general solution. Your general solution isn't correct by the way.

https://www.wolframalpha.com/input/?i=6xy%28x%29%27-4y%28x%29%3D5x%5E3%2C+y%281%29%3DD

Anonymous

Anonymous Fri 24 Jan 2020 23:40:59 No.11328616 Report

Quoted By:

>>11328577
>https://www.wolframalpha.com/input/?i=6xy%28x%29%27-4y%28x%29%3D5x%5E3%2C+y%281%29%3DD
Hmm, you're right. General was supposed to be (5/14)x^3 not x^2/3, but I guess I didn't realize there could be another variable in the solution, thought "D" had to be a real value.
Thanks

Anonymous

Anonymous Sat 25 Jan 2020 04:07:36 No.11329379 Report

Quoted By: >>11329499

>>11328525
This is pretty fucking easy, its just an integrating factor problem.
Just multiply both sides by $x^{-\frac{5}{3}}$ .

Anonymous

Anonymous Sat 25 Jan 2020 04:46:15 No.11329499 Report

Quoted By:

>>11329379
you didn't read the op moron

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