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# Partial Differentiation nature of stationary points watch

1. Hi,

I have a quick question about the "second derivative test".

Suppose you found out your stationary points and then test the coordinates in this thingy

If then the stationary point is a saddle point.

However, if I found that or , does this change anything or does the point remain a saddle?

Also does tell you anything?

2. (Original post by ManLike007)
Hi,

I have a quick question about the "second derivative test".

Suppose you found out your stationary points and then test the coordinates in this thingy

If then the stationary point is a saddle point.

However, if I found that or , does this change anything or does the point remain a saddle?

Also does tell you anything?

If then it's a saddle point regardless of whether or

implies so yes, it tells you that you have either a saddle point (if ) or the test is inconclusive (if . Alternatively, we can just say that implies no relative max/min
3. (Original post by RDKGames)
x
Ah ok I see, thank you very much sir
4. (Original post by RDKGames)
x
Really sorry to bump this thread but I require your assistance again if you don't mind!

Suppose you had two local minimum points for example, how would I determine which point is global or local?

(Just to clarify, I know both points are technically local minimum points but I want to know which one is global or not)
5. (Original post by ManLike007)
Really sorry to bump this thread but I require your assistance again if you don't mind!

Suppose you had two local minimum points for example, how would I determine which point is global or local?

(Just to clarify, I know both points are technically local minimum points but I want to know which one is global or not)
One has greater value than the other. If the point is global max/min, then takes lower/greater values for all other
6. (Original post by RDKGames)
One has greater value than the other. If the point is global max/min, then takes lower/greater values for all other
Ohhh ok, much appreciated for all your time and help

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