Finding the singular points for this differential equation

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The discussion centers on finding the singular points of the differential equation d^2/dx^2 + ln(x)y = 0. Participants clarify that the focus should be on identifying singular points rather than solving the equation. It is noted that the differential equation is not defined at x = 0, which complicates the use of power series. The confusion arises from whether to include the power series for ln(x) in the solution, leading to difficulties in comparing coefficients. Ultimately, the emphasis is on recognizing the nature of the singular points rather than performing a full solution.
JKC

Homework Statement



If d^2/dx^2 + ln(x)y = 0[/B]

Homework Equations



included in attempt

The Attempt at a Solution



I was confused as to whether I include the power series for ln(x) in the solution. It makes comparing coefficients very nasty though.

CS3DKyz.png


Whenever I expand for m=0 for the a0 I end up with a pretty nasty expansion. Can somebody tell me where I'm going wrong here?

Thanks

Note: I understand how tedious this part of calculus is so thanks in advance to anyone willing to take the time to lend a hand.
 

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JKC said:

Homework Statement



If d^2/dx^2 + ln(x)y = 0[/B]
You're missing y on the left side.
JKC said:

Homework Equations



included in attempt

The Attempt at a Solution



I was confused as to whether I include the power series for ln(x) in the solution. It makes comparing coefficients very nasty though.

View attachment 213501

Whenever I expand for m=0 for the a0 I end up with a pretty nasty expansion. Can somebody tell me where I'm going wrong here?

Thanks

Note: I understand how tedious this part of calculus is so thanks in advance to anyone willing to take the time to lend a hand.
I think you might be going about it wrong. Based on what you posted, the question is not asking you to solve the DE -- just find the singular points. Obviously you're not going to get a series in powers of x, because the DE is not defined at x = 0.
 
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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