Volume of Prism: Length & Width (y^3-y, y-1)

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Discussion Overview

The discussion revolves around determining the length and width of a swimming pool modeled as a prism, given its volume expressed as y^3-y and height as y-1. The scope includes mathematical reasoning and problem-solving related to geometry and algebra.

Discussion Character

  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant states the volume of a prism is given by the formula V=lbh and suggests substituting the known values to find length (l) and width (w).
  • Another participant sets up the equation y(y-1)(y+1)=lw(y-1) and simplifies it to y(y+1)=lw, but expresses uncertainty about how to proceed from there.
  • A subsequent reply proposes two possible configurations for the dimensions: either y units long and (y+1) units wide or (y+1) units long and y units wide, noting that without additional information, the specific dimensions cannot be determined.
  • Some participants point out that the assumption of whole integer measurements is not stated in the problem, suggesting that y could be any real value greater than 1.

Areas of Agreement / Disagreement

Participants express differing views on the assumptions regarding the nature of the measurements (whole integers vs. real values) and the implications for determining the dimensions of the pool. The discussion remains unresolved regarding the specific values of length and width.

Contextual Notes

There is a lack of clarity regarding the assumptions about the values of y, particularly whether they are restricted to integers or can be any real number greater than 1. This affects the interpretation of the results.

Markg1997
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if a swimming pool has a volume of y^3-y and a height of y-1 then what is the length and width?
 
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The volume of a prism is

[tex]V=lbh[/tex]

And so in your case, [itex]V=y^3-y[/itex] and [itex]h=y-1[/itex] so plug these in, can you then figure out what l and b must be? Hint: Factorize.
 
I have it set up as:
y(y-1)(y+1)=lw(y-1) which I then divide by (y-1) to get
y(y+1)=lw and then I am stuck
 
Markg1997 said:
I have it set up as:
y(y-1)(y+1)=lw(y-1) which I then divide by (y-1) to get
y(y+1)=lw and then I am stuck

Yer pool is either y units long and (y+1) units wide or (y+1) units long and y units wide. Without additional information, you can't tell which dimension is which.
 
That's assuming that all measurements are whole integers which was not given.
 
HallsofIvy said:
That's assuming that all measurements are whole integers which was not given.
This doesn't assume whole integers at all. y could be any real value greater than 1.
 

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