1) Find the maximum and minimum values off(x,y)=4x+y on the ellipse x2+4y2=1

2) Find the critical points for the function f(x,y)=x3+y33x23y+9

and classify each as a local maximum, local minimum, saddle point, or none of these.

Critical points:

Classifications:

3)Find the equation of the tangent plane to the surfacez=1y29x2 at the point (3,0,-81)

z= *Note: Your answer should be an expression of x and y; e.g. "3x - 4y + 6"*