Answer:
Step-by-step explanation:
Given is a function f in two variables as
To find critical points of the given function and also to find max, min or saddle point.
Find the partial derivatives
Equate first derivatives to 0
Adding fx and fy we get
x=±y
Only real roots are (x,y) =(3,3) and (-3,-3)
(3,3) is a saddle point
(-3,-3) is also a saddle point.