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2018-02-06, 12:55 AM (ISO 8601)
- Join Date
- Jan 2013
- Location
- Arkansas, U.S.
- Gender
How in the world do I solve this differential equation?
dy/dx = x(x-y)
I've been staring at this for the past half hour, and I'm completely stumped. I can't separate the variables, but I can't integrate it in this form either. I don't know what to do.
EDIT: I feel dumb now. This is dy/dx + P(x)y=Q(x).
Am I correct in thinking that P(x) can = x?Last edited by MonkeySage; 2018-02-06 at 01:03 AM.
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2018-02-06, 01:19 AM (ISO 8601)
- Join Date
- Aug 2008
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2018-02-07, 01:30 PM (ISO 8601)
- Join Date
- Sep 2013
Re: How in the world do I solve this differential equation?
My understanding is that you do this:
dy/dx = x(x-y) = (x^2) -xy
for f(y), x and x^2 are constants.
y = (x^2)y - (x/2)(y^2)
If you want y in terms of x, then divide by y on both sides and then seperate the variables.
1 = (x^2) - (x/2)y
(x/2)y = (x^2)-1
y = 2x - (2/x) or y = 2x - 2(x^-1)
I could be in error though. It's been a while since I had to do this sort of maths.