Change of Variables

Tricky....

Reduce u'' + (ax+b)u = 0 to u'' + tu = 0 by a suitable change of variables.

Let ax+b = t, then by differenciating u(x) with respect to t twice using the chain rule you will get (a^2)u'' + tu = 0. Is this what you wanted?

this can surely not be the whole story, since by just chosing your problem will already be solved...

can you give a bit more information?

I suppose it should read like this:



and you want to make a substitution such that you end up with



??