Undergrad Help getting started with this differential equation

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To solve the differential equation ∂²Φ/∂s² + (1/s)∂Φ/ds - C = 0, the substitution Ψ = dΦ/ds simplifies it to the first-order equation Ψ'(s) + (1/s)Ψ(s) = C. An integrating factor can be used to solve this first-order equation effectively. The discussion also questions the necessity of using partial derivative symbols since the equation involves only the single variable s. Clarifying the notation may help in understanding the problem better.
Daniel Sellers
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I have a fairly simple non-homogeneous second order ODE to solve but I can't seem to get started with it.
I need to solve

2Φ/∂s2 + (1/s)*∂Φ/ds - C = 0

Where s is a radial coordinate and C is a constant.

I know this is fairly simple but I haven't had to solve a problem like this in a long time. Can someone advise me on how to begin working towards a general solution?

Is the method of undetermined coefficients the correct approach?

Thanks very much.
 
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Substituting ##\Psi=d\Phi/ds## turns your equation into the first order equation ##\Psi'(s)+\frac{1}{s}\Psi(s)=C##. You should be able to do this with an integrating factor.
 
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The equation is the same as $$\frac{1}{s}\frac{\partial}{\partial s}\left(s\frac{\partial \phi}{\partial s}\right)=C$$
 
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Is there a reason for the partial derivative symbols when there is only the single variable s?
 
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