Sturm-Liouville expansion with no lambda?

renegade05

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Sep 10, 2010
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260
How would I solve this :

\(\displaystyle -(xu')'=\frac{1}{x} \ln{x} \enspace 1<x<e\)

\(\displaystyle u(1)=0 \enspace, u'(e)=0\)

I want to expand this with:

\(\displaystyle u(x) = \sum_{n=1} ^{\infty} b_n X_n(x)\)

Where \(\displaystyle X_n(x)\) are the eigenfunctions of a S-L problem.

\(\displaystyle b_n\) are some constants.

I want to express the solution as a single integral, from x = 1 to x = e.

Can someone please show me how to expand this? How can I find the eigenfunctions and the b_n. I know it is easy to solve with different methods - but I would like to do it this way to get a better grasp of similar problems. Thanks!

The lack of a lambda is really throwing me off - no idea how to do this.
 
How would I solve this :

\(\displaystyle -(xu')'=\frac{1}{x} \ln{x} \enspace 1<x<e\)

\(\displaystyle u(1)=0 \enspace, u'(e)=0\)

I want to expand this with:

\(\displaystyle u(x) = \sum_{n=1} ^{\infty} b_n X_n(x)\)

Where \(\displaystyle X_n(x)\) are the eigenfunctions of a S-L problem.

\(\displaystyle b_n\) are some constants.

I want to express the solution as a single integral, from x = 1 to x = e.

Can someone please show me how to expand this? How can I find the eigenfunctions and the b_n. I know it is easy to solve with different methods - but I would like to do it this way to get a better grasp of similar problems. Thanks!

The lack of a lambda is really throwing me off - no idea how to do this.
Strictly speaking this is not a S-L problem, it is just a normal second order ODE.
 
Strictly speaking this is not a S-L problem, it is just a normal second order ODE.

Ya, asked to find a suitable S-L problem so I can use the eigenfunctions to solve the PDE.

I managed to solve it :)

thanks!
 
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