Question

How do you show that `f(x,y)= x^4 + y^4` has a saddle point at (x,y) = (0,0)?

Answer 1

I don't believe it foes have a saddle point at `(0,0)`.

`f(0,0)=0` but for any other `(x,y)`, we have `f (x,y) >0`.

It looks like `f` has an absolute minimum at `(0,0)`.

Answer 2

I don't believe it does have a saddle point at `(0,0)`.

`f(0,0)=0` but for any other `(x,y)`, we have `f (x,y) >0`.

It looks like `f` has an absolute minimum at `(0,0)`.