\input lecture
\nopagenumbers
{\bf Math 225 : Quiz\hfill Oct 16, 1991}

Show your work and circle your final answer.

\vfill
1. Find all the critical points of $$f(x,y) = 4 y^3 + 6 y^2 x + 3 x^2 + 1$$


\vfill
2. The function $$f(x,y) =  x^4 + 2x^2 (y^2 - 1) + 2 y^2$$
has a critical point at (0,0). Determine whether this point is a local max, a local min, or a saddle point.
\bye

