# using polynomials

• Mar 27th 2009, 12:18 AM
vidalex
using polynomials
The problem states:The volume of the box is 630in^3. The height is 4 in more than the width, the length is 1 in more than than width.What is the width?

I started by forming the equation based on l*w*h=v so,

(1+w)(4+w)(w)=630 and i combined to get

w^3+5w^2+4w=630

And from this point I'm stuck
• Mar 27th 2009, 12:47 AM
craig
Your work so far is correct, rearranging the formula you have above will give you the following cubic equation:

\$\displaystyle w^3 + 5w^2 + 4w - 630 = 0\$

Have you been taught how to solve cubic equations?
• Mar 27th 2009, 01:02 AM
vidalex
No this is an extra credit problem for this unit. We've covered how to find zeros but this problem has me stumped.

Quote:

Originally Posted by craig
Your work so far is correct, rearranging the formula you have above will give you the following cubic equation:

\$\displaystyle w^3 + 5w^2 + 4w - 630 = 0\$

Have you been taught how to solve cubic equations?

• Mar 27th 2009, 04:26 AM
stapel
If you're using graphing calculators in your class, maybe you're expected to use that to find where the polynomial crosses the x-axis...?
The text passage contains a mathematical word problem about finding the width of a box given its volume and the relationships between its dimensions. The problem is formulated into a cubic equation, and the poster is stuck at this point. The responder confirms the equation and suggests the use of a graphing calculator to solve it.
single_question
Given a text passage, determine:
    1. If it contains a mathematical question (including word problems or calculations)
    2. If an answer to that mathematical question is provided in the text

First, describe the content structure you found in 1-2 sentences.

Then provide your analysis in the following format:
TYPE: <one of the following values>
- NO_QUESTION
- SINGLE_QUESTION
- SINGLE_QUESTION_WITH_ANSWER
- MULTIPLE_QUESTIONS
- MULTIPLE_QUESTIONS_WITH_ANSWERS
system
# using polynomials

• Mar 27th 2009, 12:18 AM
vidalex
using polynomials
The problem states:The volume of the box is 630in^3. The height is 4 in more than the width, the length is 1 in more than than width.What is the width?

I started by forming the equation based on l*w*h=v so,

(1+w)(4+w)(w)=630 and i combined to get

w^3+5w^2+4w=630

And from this point I'm stuck
• Mar 27th 2009, 12:47 AM
craig
Your work so far is correct, rearranging the formula you have above will give you the following cubic equation:

\$\displaystyle w^3 + 5w^2 + 4w - 630 = 0\$

Have you been taught how to solve cubic equations?
• Mar 27th 2009, 01:02 AM
vidalex
No this is an extra credit problem for this unit. We've covered how to find zeros but this problem has me stumped.

Quote:

Originally Posted by craig
Your work so far is correct, rearranging the formula you have above will give you the following cubic equation:

\$\displaystyle w^3 + 5w^2 + 4w - 630 = 0\$

Have you been taught how to solve cubic equations?

• Mar 27th 2009, 04:26 AM
stapel
If you're using graphing calculators in your class, maybe you're expected to use that to find where the polynomial crosses the x-axis...?
user
The text passage contains a mathematical word problem about finding the width of a box given its volume and the relationships between its dimensions. The problem is formulated into a cubic equation, and the poster is stuck at this point. The responder confirms the equation and suggests the use of a graphing calculator to solve it.

TYPE: SINGLE_QUESTION