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:
Step-by-step explanation:
Let the price for children and adults package be represented with x and y respectively.
For the first week the sum of the package will be as follows:
3x+8y = 126
For the two weeks after:
6x+4y= 108
So, we will be having two equations
3x+8y = 126..... (1)
6x+4y= 108.......(2)
These are simultaneous equations
From equation 1
3x+8y = 126
3x = 126-8y
X = 126-8y/3 ............. (3)
Put equation 3 into 2
6 ( 126-8y)/3 +4y = 108
756-48y/3 +4y = 108
756-48y+12y/3 = 108
Cross multiplying
756-48y+12y= 108×3
756-48y+ 12y = 324
Collecting like terms
756-324 = 48y-12y
432= 36y
Divide both sides by 36
432/36 = 36y/36
y= 12
Substituting y into equation 1
3x+8= 126
3x+96=126
3x= 126-96
3x= 30
Divide both sides by 3
3x/3 = 30/3
x = 10
Hence for each of the packages for children and adults. It will be 10 and 12 respectively.
I don’t know if you meant off or of but I will do both
25% OFF: $150
25% OF: $50
Answer:
This is the answer
Step-by-step explanation:
This is the solution, hope it helps
Answer:
look close because that is the question
Step-by-step explanation: