a.

Critical points occur where
. The exponential factor is always positive, so we have

b. As the previous answer established, the critical point occurs at (-3, 8) if
and
.
c. Check the determinant of the Hessian matrix of
:

The second-order derivatives are




so that the determinant of the Hessian is


The sign of the determinant is unchanged by the exponential term so we can ignore it. For
and
, the remaining factor in the determinant has a value of 4, which is positive. At this point we also have

which is negative, and this indicates that (-3, 8) is a local maximum.
The slope =0. Horizontal lines have a slope of 0
<u>Answer</u>
C. 39.71
<u>Explanation</u>
33 = p - 6.71
The first step is to make the like terms to be on the same side.
Add 6.71 on both sides of the eqution
33 + 6.71 = p - 6.71 + 6.71
39.71 = p
∴ p = 39.71