Just need help with the last one plsss :)))

A rectangle box with a square base and no top needs to be made using 300ft^2 of material. Find the dimensions of the box with th

Yuri [45]

The dimensions of the box are 10 ft and 5 ft

The maximum volume is 500 ft³

Step-by-step explanation:

A rectangle box with

A square base and no top
It needs to be made using 300 ft² of material
It has greatest volume

Surface area of a box without top (SA) = perimeter of base × height + area of the base

Volume of a box (V) = base area × height

Assume that the length of the side of the square base is x and the height of the box is y

∵ It needs to be made using 300 ft² of material

∴ The surface area of the box is 300 ft²

∵ Its base is a square of side length x ft

∴ Perimeter of the base = 4 × x = 4 x

∴ Area of the base = x²

∵ The height of the box = y ft

∵ SA = perimeter of base × height + area of the base

∵ SA = (4x)(y) + x²

∴ SA = 4xy + x²

∵ SA of the box = 300 ft²

- Equate the two expressions of SA

∴ 4xy + x² = 300

Now let us find y in terms of x

- Subtract x² from both sides

∴ 4xy = 300 - x²

- Divide each term by 4x to find y

∴ $y=\frac{75}{x}-\frac{1}{4}x$

∵ V = area of the base × height

∴ V = x² × y = x²y

- Substitute y by the equation of it above

∴ $V=x^{2}(\frac{75}{x}-\frac{1}{4}x)$

∴ $V=75x-\frac{1}{4}x^{3}$

∵ The volume of the box is greatest

- That means differentiate V and equate it by 0

∵ $\frac{dV}{dx}=75-\frac{3}{4}x^{2}$

∵ $\frac{dV}{dx}=0$ ⇒ greatest volume

∴ $75-\frac{3}{4}x^{2}=0$

- Subtract 75 from both sides

∴ $-\frac{3}{4}x^{2}=-75$

- Divide both sides by $-\frac{3}{4}$

∴ x² = 100

- Take √ for both sides

∴ x = 10

Substitute the value of x in the equation of y

∵ $y=\frac{75}{10}-\frac{1}{4}(10)$

∴ y = 5

The dimensions of the box are 10 ft and 5 ft

∵ $V=75x-\frac{1}{4}x^{3}$

∵ x = 10

∴ $V=75(10)-\frac{1}{4}(10)^{3}$

∴ $V=750-\frac{1}{4}(1000)$

∴ V = 750 - 250

∴ V = 500 ft³

The maximum volume is 500 ft³

Learn more:

You can learn more about the volume in brainly.com/question/6443737

#LearnwithBrainly

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2 years ago

Frank has 6 red socks, 8 black socks, and 10 white socks in his sock drawer. If Frank blindly reaches into his sock drawer, what

Firlakuza [10]

Answer:

B

Step-by-step explanation:

The first probability is 10/24, and the second is 9/23. If you multiply these two fractoins you get 15/92. 15/92 is approximately equal to 16%.

4 0

2 years ago

Number 4 please. its confusing

Deffense [45]

Answer:

63 monocotyledons

Step-by-step explanation:

some abbreviations ill be using:

monocotyledons=m

dicotyledons=d

3m / 4d

x / 84d

you need to figure out what x is

you can divide 84/4 and get 21

now that you have 21, you can multiple that number by 3

21x3=63

therefore, there are 63 monocotyledons

7 0

3 years ago

Read 2 more answers

Pedro is building a playground in the shape of a right triangle he wants to know the area of the playground to help him decide h

shusha [124]

Answer:

Amount of sand=Area of triangle(ABC)=1/2*AB*BC

Dimension of rectangle as length=BC and breadth=AB

Step-by-step explanation:

Given:

Pedro building a playground in shape of right angled triangle.

To Find:

How much sand he need to buy

And if playground changed to rectangle what will be the dimensions.

Solution:

Consider a ΔABC be the play ground vertex of playground,

And AB and BC be the sides making right angle.

The sand required to fill ground will be the amount of are covered by the ABC triangle.

So,

Area Of triangle(ABC)=1/2* base* height

Here base will be BC and height =AB

Therefore Area of Triangle(ABC)=1/2*BC*AB

Depending on the lengths of base and height amount of sand will be decided.

Now,

For Rectangle dimensions,

We know that if same sized triangles composes each other forms a rectangle.

It requires two triangle to form one rectangle as follows

(Refer the attachment)

Same sized Triangle ACD is imposed on it to from rectangle ABCD.

So dimension for rectangle will be same as the triangle

Dimension=length and breadth

i.e. length=base of triangle=BC

Breadth=Height of triangle=AB

i.e Breadth =AB.

5 0

2 years ago

Find the length of the missing side of the right triangle given the area of the two triangles find the length of the sides of th

irina [24]

From here, it looks like all three sides of the right triangle are missing. I don't see any of them in the question.

3 0

2 years ago