

Critical points occur where the gradient is zero. This is guaranteed whenever

and either

or

.
The Hessian matrix for this function looks like

and has determinant

Maxima occur whenever the determinant is positive and

. Minima occur whenever both the determinant and

are positive. Saddle points occur whenever the determinant is negative.
At

, you have a saddle point since the determinant reduces to -324, so

is the saddle point.
At

, the determinant is

and

, so

is a local maximum.
No other critical points remain, so you're done.
-7-13k would be the answer
Answer:
20 people. Because 5 already came to the party. 1/3 of his relatives came is 5, so multiply 5 by 3, then add 5. You get 20 people.
Step-by-step explanation:
Answer:
B
Step-by-step explanation:
43. 125 milliliters
45. 9 tsp
49. 6 tsp