I must be doing something wrong here.

So it's related to calculus, so I'm posting it in here.

How in the world do you find the (first) derivative of y=x^2-3x+2 with respect to x^2-3x?

I would factor it out with a u sub:
y=u+2

So... y'=u = x^2-3x?

Wolfram was no help to me at all. ._.[url=http://www.wolframalpha.com/input/?i=derivative+of+%28x%5E2-3x%2B2%29+with+respect+to+%28x%5E2-3x%29][/url]