A closed box with a square base has a surface area of 4,000 square centimeters. Express its volume as a function of the length of its base. Use derivatives.

Respuesta :

Answer:

The volume V of the box can be expressed as a function of the length of its base x as:

[tex]\[ V(x) = \frac{2000x - x^3}{2} \][/tex]

Step-by-step explanation:

Let's denote the length of the base of the box as \( x \) centimeters. Since the base is square, the width and height of the box are also \( x \) centimeters.

The surface area A of the box is given by the formula:

[tex]\[ A = 2lw + 2lh + 2wh \][/tex]

Given that the length of the base is x centimeters, we can substitute[tex]\( x \) for \( l \), \( w \), and \( h \):[/tex]

[tex]\[ 4000 = 2x^2 + 2xh + 2xh \][/tex]

[tex]\[ 4000 = 2x^2 + 4xh \][/tex]

To express the volume  V of the box as a function of the length of its base x, we need to first solve for the height h  in terms of x, and then use it to express the volume.

From the equation [tex]\( 4000 = 2x^2 + 4xh \), we can solve for \( h \)[/tex]:

[tex]\[ 4000 = 2x^2 + 4xh \][/tex]

[tex]\[ 2000 = x^2 + 2xh \][/tex]

[tex]\[ 2xh = 2000 - x^2 \][/tex]

[tex]\[ h = \frac{2000 - x^2}{2x} \][/tex]

Now, the volume V of the box is given by the formula:

[tex]\[ V = l.w.h \][/tex]

Substituting the expressions for[tex]\( l \), \( w \), and \( h \):[/tex]

[tex]\[ V(x) = x \times x \times \frac{2000 - x^2}{2x} \][/tex]

[tex]\[ V(x) = \frac{x^2(2000 - x^2)}{2x} \][/tex]

[tex]\[ V(x) = \frac{x(2000 - x^2)}{2} \][/tex]

[tex]\[ V(x) = \frac{2000x - x^3}{2} \][/tex]

So, the volume V of the box can be expressed as a function of the length of its base x as:

[tex]\[ V(x) = \frac{2000x - x^3}{2} \][/tex]