Question

Suppose an airline policy states that all baggage must be box shaped with a sum of length, width, and height not exceeding 174 in. What are the dimensions and volume of a square-based box with the greatest volume under these conditions? Write a function for the volume V of the box in terms of w, one of the edges of the square bottom. (Type an expression.) The interval of interest of the objective function is (Simplify your answer. Type your answer in interval notation.) The length of the square-end edge isn. The box height is in. The greatest volume of the box is in.3

Answer 1

Answer:

The square-based box with the greatest volume under the condition that the sum of length, width, and heigth does not exceed 174 in is a cube with each edge of 58 in and a volume of $195112 in^{3}$

Step-by-step explanation:

For this problem we have two constraints, that are as follows:

1) Sum of length, width, and heigth not exceeding 174 in

2) Lenght and width have the same measure (square-based box)

We know that volume is equal to the product of all three edges, and with the two conditions into account we have the next function:

$V=(w^{2})(174-2w)\\V=174w^{2}-2w^{3}$

The interval of interest of the objective function is [0, 87]

This problem requieres that we maximize the function that defines the volume. We start calculating the derivative of the function, wich is:

$V'=348w-6w^{2} \\V'=(348-6w)(w)$

We need to remember that the derivative of a function represents the slope of said function at a given point. The maximum value of the function will have a slope equal to zero.

So we find the value in wich the derivative equals zero:

$0=(348-6w)(w)\\w_1=0\\w_2=348/6=58$

The first value ($w=0$) will leave us with a 'height-only box', so the answer must be $w=58 in$

The value is between the interval of interest.

And, once we solve for the constraints, we have that:

Lenght = Width = Heigth = 58 in

Volume = $195112 in^{2}$