A rectangular box open at the is to form a rectangular piece of cardboard which is 3m*8m.what size of square should be cut from each corner to form the box with maximum volume?

v = x(3-2x)(8-2x) = 4x^3-22x^2+24x

dv/dx = 12x^2 - 44x + 24 = 4(3x^2 - 11x + 6)
so, where does dv/dx = 0?

Exalient

To find the size of the square that should be cut from each corner to form the box with the maximum volume, we can follow these step-by-step instructions:

Step 1: Determine the dimensions of the box:
Since the rectangular piece of cardboard has dimensions 3m by 8m, these will be the dimensions of the base of the box.

Step 2: Let 'x' be the length of each side of the square cut from each corner:
When each square is cut out from the corners, the length of the box will be reduced by twice 'x', and the width will be reduced by twice 'x'. Therefore, the length of the base of the box will become (3 - 2x) meters, and the width will become (8 - 2x) meters.

Step 3: Calculate the volume of the box:
The volume of the box can be calculated by multiplying the length, width, and height. Since the box is rectangular, the height will be equal to 'x' meters.

Volume = (3 - 2x) * (8 - 2x) * x
= (24x - 6x^2 - 16x + 4x^2) * x
= (4x^3 - 10x^2 + 24x) cubic meters

Step 4: Find the maximum volume:
To find the maximum volume, we need to determine the value of 'x' that maximizes the volume. We can do this by finding the derivative of the volume equation, setting it to zero, and solving for 'x'.

Volume' = 12x^2 - 20x + 24

Setting Volume' to zero:
12x^2 - 20x + 24 = 0

Using the quadratic formula:
x = (-(-20) ± √((-20)^2 - 4(12)(24))) / (2(12))
x = (20 ± √(400 - 1152)) / 24
x = (20 ± √(-752)) / 24

Since the square root of a negative value is not real, we can conclude that there is no real solution for 'x'. Therefore, there is no maximum volume for a box that can be formed from the given dimensions of the cardboard.

To find the size of the square that should be cut from each corner to form a rectangular box with maximum volume, we need to follow these steps:

Step 1: Visualize the problem:
Imagine a rectangular piece of cardboard with dimensions 3m*8m. Let's label the longer side as "L" and the shorter side as "S". We want to cut squares from each corner of the cardboard and fold it to form an open-top rectangular box. The size of the squares to be cut will determine the dimensions of the resulting box.

Step 2: Identify the variables:
Let's assume that the side length of the square to be cut from each corner is "x" meters. This means that when we fold the cardboard, the resulting width and length of the base of the box will be "L - 2x" and "S - 2x," respectively. The height of the box will be equal to the value of "x".

Step 3: Formulate the volume equation:
The volume of the box can be calculated by multiplying the length, width, and height. In this case, the volume (V) is given by: V = (L - 2x)(S - 2x)(x).

Step 4: Simplify the equation:
Using the given dimensions, we have V = (3 - 2x)(8 - 2x)(x).

Step 5: Determine the maximum volume:
To find the maximum volume, take the derivative of V with respect to x, set it equal to zero, and solve for x. Taking the derivative and solving for x is a calculus process, which involves some mathematical steps.

Step 6: Calculate x and verify the maximum volume:
Once you have found the value of x, substitute it back into the volume equation to calculate the maximum volume. Be sure to check that the value of x satisfies certain conditions, such as being within the allowed range or making physical sense for the problem context.

Note: In this case, to maximize the volume, you need to take the derivative and find the x value that satisfies the condition 0 < x < S/2 and 0 < x < L/2.

Since this involves detailed calculations that are better done using symbolic mathematics, it's recommended to use a mathematical software application like Mathematica, MATLAB, or an online symbolic calculator to carry out the calculations and find the solution.