Chapter 13.3, Problem 120E

a)

To determine

To calculate:

$\frac{{\partial }^{2}z}{\partial x^2}$ and $\frac{{\partial }^{2}z}{\partial y^2}$

b)

To determine

b)

To calculate:

Determine the concavity of traces of parallel to the $xz$ -plane. Interpret the result in the context of the problem

c)

To determine

To calculate:

Determine the concavity of traces of parallel to the $yz$ -plane. Interpret the result in the context of the problem