MATH 0240 Midterm: MATH 240 Practice Problems-90

I. Suppose the tangent plane to the surface z = f(x,y) is horizontal at (z,y)-(1,1). Also assume at that point, -4, fyyー2,左,-1, and all second partial derivatives are continuous. Determine if it is a local maximum, a local minimum or a saddle point.

1. Suppose the tangent plane to the surface z = /(x,y) is horizontal at (x,y) = (1,1). Also assume at that point, fe,-4, fey-2, fe,-1, and all second partial derivatives are continuous. Determine if it is a local maximum, a local minimum or a saddle point

1. Suppose the tangent plane to the surface z- f(x,y) is horizontal at (z, y) _ (1,1). Also assume at that point, f.-4, fyy-2, fry-1, and all second partial derivatives are continuous. Determine if it is a local maximum, a local minimum or a saddle point.