Answer:
a)
.
b) 
Step-by-step explanation:
Given a function
, this function has the following gradient:
.
(a) find the gradient of f
We have that
. So


.
.

(b) find the directional derivative of f at (2, 4, 0) in the direction of v = i + 3j − k.
The directional derivate is the scalar product between the gradient at (2,4,0) and the unit vector of v.
We have that:

.

The vector is 
To use v as an unitary vector, we divide each component of v by the norm of v.

So

Now, we can calculate the scalar product that is the directional derivative.

Answer:
4-9 = 4+(-9)
-6-7 = -6+(-7)
-4-(-9) = -4 + 9
6-(-7) = 6+7
Step-by-step explanation:
Double negatives means a positive and one positive and one negative is a negative.
Please give brainliest. I am working hard to get it.
The answer is D.
explain:
A^2 + b^2 = c^2
7 mphs faster...............

what is the average cost of 7 articles if 3 of them cost 30k each and the rest cost 12.5k each

TOTAL NUMBER OF ARTICLE= 7
ARTICLES FOR 30K = 3
ARTICLES FOR 12.5K = 7-3= 4

Average cost of 7 articles



