Quote Originally Posted by U-God View Post
Thanks again,

I handed my work in and it all looks good, however some of my friends said that they did it by using the form $\displaystyle x (A \cos x + B \sin x) $.
You said here that that form wouldn't work and to move on to the next form up, so out of interest when I got home I tried it with form: $\displaystyle x (A \cos x + B \sin x) $ and lo and behold I got the same answer as with form: $\displaystyle (x + C x^2) (A \cos x + B \sin x)$.

Does that mean I did something wrong?
It's the most general form .... If you got the same answer using $\displaystyle x (A \cos x + B \sin x) $ that would mean C = 0.

Actually I thought I read somewhere in a thread that trying $\displaystyle x (A \cos x + B \sin x) $ didn't work, but I must have only imagined I saw it.