Answer:
x = 21
Step-by-step explanation:
-7 ( x + 1 ) - 3 = -8x + 11
-7x - 7 - 3 = -8x + 11
x = 7 + 3 + 11
x = 21
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:
7,200
Step-by-step explanation:
Solve for x by plugging in y, then plug x back in