Find all local extrema of $f(x, y) = x^2 + y^2$. That is, find their locations and values.


I started this problem but when I took the first derivative I got the critical points as $(0, 0)$. Then I took the second derivative and got $x= 2$ and $y= 2$. What do i do next? Please help me. 


Question: What does biting off the Pitum have to do with Pregnancy?
Answer: According to some the sin of the Eitz HaDaas was with a Esrog tree. Through this came the curse of pain by child birth. When the lady bites the Pittum she is saying "just like I have no enjoyment now, I had no enjoyment then (at the sin of the Eitz HaDaas). Taamei HaMinhagim Likutim 68