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.

Hi there!
The correct answer for you is 270.88.
To round to the hundreth's place (.0<u>1</u><u />), you need to take the number in the thousand's place (.00<u>1</u>), and determine if the number needs to go up or down.
If the number in the thousand's place is <u>greater</u> than 4, then the number goes up.
360.72<u>7</u> --> This means that the hundreth's number goes up to 3.
If the number in the thousand's place is <u>lesser</u> than 5, then that number stays the same.
89.85<u>2</u> --> This means that the hundreth's number stays the same.
After you round, then just subtract:
360.73 - 89.85 = 270.88.
I hope this helps!
Brady
<u />
Answer:

Step-by-step explanation:
Let the total amount be x
Then Ali got 1/8x With 7/8x left
Juma got 7/40x with 7/10x left
Musa, Khalid and Mustafa got 7/30x each
since 
7x=18000
