For the equation : I have split up the particular solution into two parts, so that I have

and

which gives me

and

The solution of the corresponding homogeneous equation is of course . So for my answer I get

Where did I go wrong?

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- Nov 13th 2008, 07:36 PMpetition EdgecombeMethod of Undetermined Coefficients
For the equation : I have split up the particular solution into two parts, so that I have

and

which gives me

and

The solution of the corresponding homogeneous equation is of course . So for my answer I get

Where did I go wrong? - Nov 13th 2008, 07:53 PMmr fantastic
- Nov 14th 2008, 12:27 AMpetition Edgecombe
I did have , but I forgot how I got it, so I changed it (that's why I edited my post).

I see what I did there. I included the 3 in the initial guess so that it looked like

instead of

Quote:

http://www.mathhelpforum.com/math-he...5cb82bb7-1.gif Mr F says: This is wrong. Show all your working on how you got it (when you do this you will probably realise for yourself why it's wrong).

- Nov 14th 2008, 12:36 AMmr fantastic
- Nov 14th 2008, 01:11 AMpetition Edgecombe

And

So my problem was with the method of equating coefficients, as I had thought. - Nov 14th 2008, 03:15 AMJason Bourne