Given parameters:
First point = (12, -5)
Second point = (10, -4)
Unknown:
Slope of the line = ?
Slope is simply the vertical rise divided by the horizontal distance.
Slope = 
Simply to find slope;
Slope = 
First point = (12, -5), x₁ = 12 and y₁ = -5
Second point = (10, -4), x₂ = 10 and y₂ = -4
Input the parameters:
Slope = 
= 
= - 
The slope of the line is -
In the table it shows that 1 hour corresponds to $25. Or if you want to check it, simply take any value and divide it by its corresponding hour ( ex. 50/2 or 75/3) Hope this helps!
Answer:



Step-by-step explanation:
<u>Optimizing With Derivatives
</u>
The procedure to optimize a function (find its maximum or minimum) consists in
:
- Produce a function which depends on only one variable
- Compute the first derivative and set it equal to 0
- Find the values for the variable, called critical points
- Compute the second derivative
- Evaluate the second derivative in the critical points. If it results positive, the critical point is a minimum, if it's negative, the critical point is a maximum
We know a cylinder has a volume of 4
. The volume of a cylinder is given by

Equating it to 4

Let's solve for h

A cylinder with an open-top has only one circle as the shape of the lid and has a lateral area computed as a rectangle of height h and base equal to the length of a circle. Thus, the total area of the material to make the cylinder is

Replacing the formula of h

Simplifying

We have the function of the area in terms of one variable. Now we compute the first derivative and equal it to zero

Rearranging

Solving for r

![\displaystyle r=\sqrt[3]{\frac{4}{\pi }}\approx 1.084\ feet](https://tex.z-dn.net/?f=%5Cdisplaystyle%20r%3D%5Csqrt%5B3%5D%7B%5Cfrac%7B4%7D%7B%5Cpi%20%7D%7D%5Capprox%201.084%5C%20feet)
Computing h

We can see the height and the radius are of the same size. We check if the critical point is a maximum or a minimum by computing the second derivative

We can see it will be always positive regardless of the value of r (assumed positive too), so the critical point is a minimum.
The minimum area is


105 × $8.72 = $915.60
$915.60 + $348 = $1,263.60
Mary paid $1,263.60 for the stock.