1) Stop thinking like this. Really, just stop it.
2) Figure it out. It is likely that you have been told to find where the first derivative is zero. This is an excellent place to start finding minima and maxima.
3) No one should care where you put exponents. If you realy, REALLY hate negative exponents, move them. Perhaps it would be convenient to move negative exponents from the numberator to their corresponding positive exponents in the denominator. On the other hand, it may not be particularly convenient.
4) Did I mention that you should stop beating yourself up?