Postal regulations specify that a parcel sent by priority mail may have a combined length and girth of no more than 144 in. Find the dimensions of a rectangular package that has a square cross section and largest volume that may be sent by priority mail.What is the volume in such a package?

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Answer:

The volume in such a package is 27648 in³

Step-by-step explanation:

Consider the provided information.

Postal regulations specify that a parcel sent by priority mail may have a combined length and girth of no more than 144 in.

Let the dimension are x by x by y.

Where x is the variable for the square base package and y is the variable for length.

Thus l=x, b=x and h=y

Then the volume of the box is: [tex]V(x)=x^2y[/tex] (∵V=lbh)

The maximum combined length and girth is 144.

Therefore, [tex]4x+y=144[/tex]

[tex]y=144-4x[/tex]

Substitute the value of y in volume of the box.

[tex]V(x)=x^2(144-4x)[/tex]

[tex]V(x)=144x^2-4x^3[/tex]

[tex]V'(x)=288x-12x^2[/tex]

Substitute V'(x)=0.

[tex]0=288x-12x^2[/tex]

[tex]12x(24-x)=0[/tex]

[tex]x=0\ or\ x=24[/tex]

Now apply second derivative test.

[tex]V''(x)=288-24x[/tex]

[tex]V''(0)=288-24(0)>0[/tex] (Min)

[tex]V''(24)=288-24(24)<0[/tex] (Max)

Hence, the maximum volume is at x=24

If x=24 then [tex]y=144-4(24)=48[/tex]

Substituting value of x = 24 and y = 48 [tex]V(x)=x^2y[/tex] gives 27648.

Hence, the volume in such a package is 27648 in³

If parcel sent by priority mail may have a combined length and girth of no more than 144 in and rectangular package has a square cross section has possible largest volume is 27648.

What is volume ?

Amount of space occupied by a 3D object  is known as volume.

Here given that  parcel sent by priority mail may have a combined length and girth of no more than 144 in and rectangular package has a square cross section .

Let suppose

Length=Breadth =x

Height=y

Hence volume can be written as

[tex]V=x^{2}y[/tex]

Now combined length and girth can be written as

4x+y=144

y=144-4x

Hence

[tex]$\begin{aligned}&V(x)=x^{2}(144-4 x) \\&V(x)=144 x^{2}-4 x^{3} \end{aligned}$[/tex]

Now differentiating with respect to x

[tex]V^{\prime}(x)=288 x-12 x^{2}[/tex]

Now for maximum value

[tex]V^{\prime}(x)=0[/tex]

[tex]$\begin{aligned}&0=288 x-12 x^{2} \\&12 x(24-x)=0 \\&x=0 \text { or } x=24\end{aligned}$[/tex]

Now differentiating again with respect to x

[tex]$\begin{aligned}&V^{\prime \prime}(x)=288-24 x \\&V^{\prime \prime}(0)=288-24(0) > 0 \text { (Min) } \\&V^{\prime \prime}(24)=288-24(24) < 0 \text { (Max) }\end{aligned}$[/tex]

So maximum volume

[tex]V_{max}=V(24)=24^2(144-4\times24)\\\\V_{max}=576(48)\\\\V_{max}=27648[/tex]

If parcel sent by priority mail may have a combined length and girth of no more than 144 in and rectangular package has a square cross section has possible largest volume is 27648.

To learn more about volume visit :https://brainly.com/question/1972490

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