First you need to find your critical points to do this. take the dervitive of that function and set it = to 0.
Can't remember the quotent rule right now i think it's if F(x)=a/b then f'(s) = (b')a-(a')b/(b^2)
f'(x)= 2ax .....= 0
then just solve for all values a and x that make it = 0 that will tell you where you'r critical points are. put those in the equation and see what it does.
When answering a question from a poster on Math Help Forum it is generaly considered good form to attempt to answer that question not some other question. You will also find this a usefull exam technique in its own right.