Question

50 POINTS HELP PLEASE MATH BE RIGHT

A box without a top is to be made to hold copious bags of candy. It is made
from a rectangular piece of cardboard, with dimensions: width choose a number
between 1.5 ft and 3.5 ft _______ and length choose a number between 4 ft and 6ft
_______, by cutting out square corners with side length
x
and folding up the sides.Unit 7 Test, Part 2:
Modeling with Geometry
Total score: 15 points
Answer the following questions, showing all of your work. Submit your work to the
assignment box.
NOTICE how the points are broken down above each problem.
This lets you know what information is mandatory to give me in your answer.
(5 total points - 1 point correct equation for volume, 1 point correct value for x; 1
point explanation for finding x; 2 points explanation of what x- and y- coordinates
represent)
1)
A box without a top is to be made to hold copious bags of candy. It is made
from a rectangular piece of cardboard, with dimensions: width choose a number
between 1.5 ft and 3.5 ft _______ and length choose a number between 4 ft and 6ft
_______, by cutting out square corners with side length
x
and folding up the sides.
(a)
Write an equation for the volume
V
of the box in terms of
x
.
(b)
Use Desmos to graph and estimate the value of
x
,
to the nearest tenth
, that
gives the greatest volume. Explain your process. Post a snapshot of your graph
with your work.
(c)
Explain what the x- and y-coordinates represent in your eqution

Answer 1

Let the length of the side of the square being cut out equal x

The length of the box would be 4.5 - 2x

The width of the box would be 3 -2x

Volume = (4.5 -2x) * (3-2x) * x

Simplify to:

V = 4x^3 - 15x^2 + 13.5x

B See picture: The greatest volume would be the point of the highest curve.

x = 0.589 y = 3.565, Rounded to the nearest tenth x = 0.6

Process: entered the equation from A into Desmos. The Y value would be the volume, so found where the volume was the highest and then found the related x value.

C) X is the side length of the corner squares being cut out, which would also be the height of the box. The Y value is the volume of the box.