One more undetermined coefficients problem

[Daniel_Feldman]

I just need the guess...

-7y''-7y=sin(x)

The normal guess would be Asin(x)+Bcos(x), but here when I find 6'' and plug them in, I get all terms canceling and get 0. I'm not sure how to approach this....

 

[royhaas]

Try \(\displaystyle $kx cos(x)\)