Chapter 8.3, Problem 7P

To determine

(a)

If the function $f_x\left(4,1\right)$ is positive, negative or nearly zero.

To determine

(b)

If the function $f_y\left(4,1\right)$ is positive, negative or nearly zero.

To determine

(c)

If the function $f_x\left(5,2\right)$ is positive, negative or nearly zero.

To determine

(d)

If the function $f_y\left(5,2\right)$ is positive, negative or nearly zero.