Suppose thathas continuous second partial derivatives in a neighbourhood of
and that
at
Defineat
Form the discriminant
If
then
is a saddle point.
Ifthen
has a local minimum at
Ifand a local maximum at
if
Suppose thathas continuous second partial derivatives in a neighbourhood of
and that
at
Defineat
Form the discriminant
If
then
is a saddle point.
Ifthen
has a local minimum at
Ifand a local maximum at
if