13-07-2024

Problem: Let $f,g : \mathbb{R} ^2 \to \mathbb{R} $ be defined by \[ f(x,y) = x^2 - \frac{3}{2}xy^2 \text{ and } g(x,y) = 4x^4 - 5x^2 y + y^2 \] for all $(x,y) \in \mathbb{R} ^2$.

Consider the following statements:
  • P: $f$ has a saddle point at $(0,0)$.
  • Q: $g$ has a saddle point at $(0,0)$.
Then
  • both P and Q are TRUE
  • P is FALSE but Q is TRUE
  • P is TRUE but Q is FALSE
  • both P and Q are FALSE
Solution: I encourage you to attempt to solve the problem today. The solution will be provided tomorrow. This will give you the opportunity to test your understanding of the problem and to improve your skills in solving similar problems in the future.