A rectangular storage container with an open top is to have a volume of 10 cubic meters. The length of its base is twice the width. Material for the base costs $10 per square meter. Material for the sides costs $6 per square meter. Find the cost of materials for the cheapest such container. Be sure to justify that the cost you find is the cheapest cost for this container

Respuesta :

Answer:163.54$

Step-by-step explanation:

Given data

Volume of Storage(V)=[tex]{10m^3}[/tex]

Length=2breadth

Let Length be L,Breadth be & height be H

therefore

10=LBH

Now substitutes the values

10=2[tex]{B^2}H[/tex]

5=[tex]{B^2}H[/tex]

Now cost for base is [tex]{C_1}=2{B^2}\times10[/tex]

Cost for side walls is[tex]{C_2}={2LH}\times6+2BH}\times6[/tex]

Now total cost(C)=[tex]{C_1}+{C_2}[/tex]

C=20[tex]{B^2}H[/tex]+[tex]{2LH}\times6[/tex]+[tex]2BH}\times6[/tex]

C=20[tex]{B^2}H[/tex]+24BH+[tex]12BH[/tex]

C=[tex]20{B^2}+36B\times\frac{5}{B^{2}}[/tex]

Now Differentiating With respect to Breadth to get minimum cost

[tex]\frac{\mathrm{d} C}{\mathrm{d} B}=0[/tex]

[tex]we\ get\ B=\sqrt[3]{4.5}=1.65m[/tex]

[tex]L=3.30m[/tex]

[tex]H=1.836m[/tex]

and mimimum cost C

[tex]{C=163.54\$}[/tex]