Wednesday

October 22, 2014

October 22, 2014

Posted by **Kim** on Tuesday, January 4, 2011 at 8:06pm.

A. write a function A to represent the area of the base of the box in terms of x.

B. What is a reasonable domain for the function A?

C. Write an equation if the area of the base must be 416in^2

D. Solve the equation in part C for the values of x in the reasonable domain

What are the dimensions of the base of the box.

- Math -
**Reiny**, Tuesday, January 4, 2011 at 9:06pmlength of base = 30-2x

width = 20-2x

Area of base = (30-2x)(20-2x)

clearly 20-x and 30-2x have to be positve, or

0 < x < 10

(30-2x)(20-2x) = 416

600 - 100x + 2x^2 = 416

2x^2 - 100x + 184

x^2 - 50x + 92 = 0

I will complete the square

x^2 - 50x + 625 = -92 + 625

(x-25)^2 = 533

x-25 = ± √533

x = 25 ± √533

so staying within the domain x = 25+√533

or appr. 1.91

- Math -
**rj**, Wednesday, January 5, 2011 at 7:37pm7+7

**Answer this Question**

**Related Questions**

math - A box with a square base and no top is to be made from a square piece of ...

math - an open box is to be formed out of a rectangular piece of cardboard whose...

Algebra - A box with a square base and no top is to be made from a square piece ...

Calculus - Squares with sides of length x are cut out of each corner of a ...

Calculus - From each corner of a square piece of cardboard, remove a square of ...

algebra - A rectangular piece of cardboard is 2 units longer than it is wide? ...

math - a piece of cardboard is twice as it is wide. It is to be made into a box ...

Math- Math Analysis - In a rectangular piece of cardboard with a perimeter of ...

Algebra - A rectangular piece of cardboard is 15 inches longer than it is wide. ...

calculus - Help!!! A rectangle piece of cardboard twice as long as wide is to be...