- #1

asdf1

- 734

- 0

but

There's one thing I don't understand:

If y`` +p(x)y` + q(x)y=0 ...equation 1.

and you have this equation:

u``y1 + u`(2y`1+py1) + u(y``1+py`1+qy1)=0 ...equation 2

and y1 is a solution of equation 1

then why is "u" gone in equation 1?

:P