What does it mean to evaluate f(x,y) at Critical Points to determine Gobal Max and Min? I have found the Points I just need to work out if they are Global/Absolute Max/Mins and I don't know how to do that. Thanks :)

Question

jim_thompson5910 · Answer

If you have your critical points, why not plug them into f(x,y) and then compare to see which points yield the largest output? That will give you the global max. 

I think you consider boundary points as well.

anonymous · Answer

oh...is it that simple. Haha! I was thinking it was something confusing. So if you sub (0,1) into the equation and got 0 and then sub in (sqrt(2),0) into the equation and got 1, that second point would be the max? (this is just an example, I understand I would need to do this for all points)

jim_thompson5910 · Answer

yes I would think that (sqrt(2),0) is at the global max (which is 1). This is assuming you've checked all critical points and boundary points and found that f(x,y) = 1 is the largest output.