Solving an ODE by the method of Integrating Factors

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The discussion centers on solving the ordinary differential equation (ODE) y' + y = x y²/3 using the method of integrating factors. The challenge arises because the term Q is a function of both x and y, unlike typical examples where Q depends solely on x. Attempts to manipulate the equation lead to confusion, particularly with the term in front of y' and the need to express the right-hand side as a function of x only. A key insight is recognizing that the right-hand side can be rewritten as x e^(x/3) (e^x y)²/3, which may facilitate finding a solution. The conversation highlights the complexities of applying integrating factors when dealing with non-standard forms of ODEs.
1missing
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1. y' + y = x y2/32. The problem states we need to solve this ODE by using the method of integrating factors. Every example I found on the internet involving this method was of the form:

y' + Py = Q

Where P and Q are functions of x only. In the problem I was given however, Q is a function of both x and y. If I try to proceed with the method I end up with:

(d/dx) ex y = x ex y2/3


Annnnd that's where I'm stuck. Am I missing something here or was this problem incorrectly assigned?
 
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So what do you have to do to make the right-hand side a function in ##x## only ?
 
Divide by y2/3 on both sides of the original equation, but then I've got a term in front of the y' and that doesn't seem to get me closer to a solution.
 
What is ##\frac{d(y^{1/3})}{dx}## equal to?
 
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Son of a...I probably would've stared at this thing for a couple of days before I noticed that. That should get me to a solution, let me give it a go.
 
1missing said:
I end up with:
(d/dx) ex y = x ex y2/3

Annnnd that's where I'm stuck. Am I missing something here or was this problem incorrectly assigned?
You could also proceed by noting that the righthand side is equal to ##x e^{x/3} (e^x y)^{2/3}##.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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