3 Written Questions

1. Fxx and Fyy < 0
2. sin(2x)
3. sin(x)cos(y) + cos(x)sin(y)

3 Multiple Choice Questions

1. fxx*fyy - fxy^2
   1. Min
   2. D =
   3. Max
   4. cos(2x) =
2. cos^2(x) - sin^2(x)
   1. sin(x + y) =
   2. Max
   3. cos(2x) =
   4. D =
3. Fxx and Fyy > 0
   1. Min
   2. Max
   3. cos(2x) =
   4. D =

2 True/False Question

1. Local max or min → D > 0
   

   True        False

2. Saddlepoint → Fxx and Fyy > 0
   

   True        False