[MOVED] optimization: A cylindrical container costs....

[ashley123456789]

A cylindrical container costs $2.00 per square foot for the sides and $3.00 a square foot for the top and bottom. The container must hold 100 cubic feet of material. What are the dimensions of the most economical container.

I hope someone sees this and answers it quickly because I need it tomorow morning. So if you know this please answer, it would help alot. thanks

 

[jacket81]

Okay, the equation for cost of material is (2*h*2*pi*r)+(3*2*pi*r^2) with h being height and r being radius.

Now eqaution for volume is pi*r^2*h=100, or h=100/(pi*r^2).

Substitute that for h in previous equation, (400/r)+(6*pi*r^2).

So, differienate and set to 0, -400/r^2 + 12*pi*r=0.
Or 400/r^2=12*pi*r, or 12*pi*r^3 = 400, or r^3=400/(12*pi).

Now, if I didnt make I mistake, i hope that helps.

 

[Denis]

I hope someone sees this and answers it quickly because I need it tomorow morning.

WHY? Homework due then?

 

[galactus]

I hope someone sees this and answers it quickly because I need it tomorow morning.

WHY? Homework due then?

Hey Denis:

I answered this on another site and it was promptly deleted.

Wonder why?. :roll: