Thursday

July 31, 2014

July 31, 2014

Posted by **math dave** on Wednesday, April 17, 2013 at 10:36pm.

- math -
**Reiny**, Wednesday, April 17, 2013 at 11:18pmlet the base be x by x

let the height be y

x^ y = volume

x^2 y = 320

y = 320/x^2

cost = 15x^2 + 10x^2 + 4(2.5)xy

= 25x^2 + 10x(320/x^2)

= 25x^2 + 3200/x

d(cost)/dx = 50x - 3200/x^2 = 0 for a min of cost

50x = 3200/x^2

x^3 = 64

x = 4

then y = 320/16 = 20

the box should have a base of 4 by 4 and a height of 20 units

**Related Questions**

Calculus - dimensions of a box? - A rectangular box with a square bottom and a ...

Calc - A closed box with a square base is to be constructed so that its volume ...

Algebra - A rectangular box with the volume 320 cu ft is built with a square ...

Calculus - A box is constructed out of two different types of metal. The metal ...

calculus - A box is constructed out of two different types of metal. The metal ...

math - A rectangular box with a square base and top is to be made to contain ...

Calculus - A rectangular box with a square base and top is to be made to contain...

calculus - a rectangular box is to have a square base and a volume of 20 ft ...

CALC - An open box is to be constructed so that the length of the base is 4 ...

Calculus - A rectangular box with square base (which is NOT necessarily a cube) ...