Is it 2nd order polynomials, or 2nd order quadratics?

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    2nd order Polynomials
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Discussion Overview

The discussion revolves around the classification and manipulation of second-order polynomials, specifically whether they should be referred to as "2nd order polynomials" or "2nd order quadratics." Participants explore various mathematical transformations and definitions related to these polynomials.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant presents a method for defining the roots of a polynomial in the form (ax + b)(cx + d) and expresses confusion about the terminology used for second-order polynomials.
  • Another participant extends the discussion to third-order polynomials, providing a similar structure for defining roots and suggesting relationships between the roots.
  • A participant challenges the validity of a transformation made in the original polynomial, arguing that the substitution of x with s does not yield a correct representation of the roots.
  • Further clarification is sought regarding the implications of changing variables and the significance of the term "False x" introduced by one participant.
  • Participants express interest in the reasoning behind the transformations rather than just the results, indicating a focus on the process of mathematical exploration.

Areas of Agreement / Disagreement

There is no consensus on the terminology for second-order polynomials, and participants express differing views on the validity of certain mathematical transformations. The discussion remains unresolved regarding the correctness of the proposed methods and definitions.

Contextual Notes

Some participants note potential issues with variable substitution and the implications of defining new variables, but these concerns are not fully resolved within the discussion.

Mol_Bolom
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I thought this was rather odd, and wanted to just show it to see what you all thought of it. Well, also, if anyone knows what I should read to exactly understand what I did.

1: Let's define each answer of a polynomial such as (ax + b)(cx + d) as x1 = (-b/a), x2 = (-d/c).

2: The polynomial written out is qx^2 + rx + s

3: Change the polynomial from qx^2 + rx + s to where x = s, and rewrite the problem as qS^2 + rS = S.

4: Devide S out, which leaves qS + r = 1

5: subtract r, qS + r - r = 1 - r. qS = 1 - r

6: Devide q, qS/q = (1 - r)/q. S = (1-r)/q

7: Now if the equation (q x1 + 1)/q is subtracted from S will solve for x2. Or if x1 is replaced with x2 the equation then solves for x1.
(1-r)/q - (q x1 + 1)/q = x2
(1-r)/q - (q x2 + 1)/q = x1

I did simplify this, but I still think it is rather interesting as to 'how' I did this, rather than the 'simplicity' of it.
(Darn it, I forgot what these kinds of polynomials are called. Is it 2nd order polynomials, or 2nd order quadratics?)

Thanks
 
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I just ran it through a couple of problems but it seems that in the third order...

qx3 + rx2+sx+t
(ax+b)(cx+d)(ex+f)
x1 = -b/a
x2 = -d/c
x3 = -f/e

(1-r)/q - (q x1 + 1)/q = x2 + x3
(1-r)/q - (q x2 + 1)/q = x1 + x3
(1-r)/q - (q x3 + 1)/q = x1 + x2
 
Last edited:
3: Change the polynomial from qx^2 + rx + s to where x = s, and rewrite the problem as qS^2 + rS = S.
The original polynomial is 0 only at its roots. x=s is NOT a root, so your rewrite is wrong. Also you put in a sign change in the S term.
 
Mol_Bolom said:
I thought this was rather odd, and wanted to just show it to see what you all thought of it. Well, also, if anyone knows what I should read to exactly understand what I did.

1: Let's define each answer of a polynomial such as (ax + b)(cx + d) as x1 = (-b/a), x2 = (-d/c).

2: The polynomial written out is qx^2 + rx + s

3: Change the polynomial from qx^2 + rx + s to
To what?? Isn't that a crucial part of the problem?

where x = s, and rewrite the problem as qS^2 + rS = S.

4: Devide S out, which leaves qS + r = 1

5: subtract r, qS + r - r = 1 - r. qS = 1 - r

6: Devide q, qS/q = (1 - r)/q. S = (1-r)/q

7: Now if the equation (q x1 + 1)/q is subtracted from S will solve for x2. Or if x1 is replaced with x2 the equation then solves for x1.
(1-r)/q - (q x1 + 1)/q = x2
(1-r)/q - (q x2 + 1)/q = x1

I did simplify this, but I still think it is rather interesting as to 'how' I did this, rather than the 'simplicity' of it.
(Darn it, I forgot what these kinds of polynomials are called. Is it 2nd order polynomials, or 2nd order quadratics?)

Thanks
 
Yikes...I had thought I did a better job at explaining it, I guess not...Well back to the drawing board...

I just thought it was interesting how I came up with it...

I'll try one more time, though...


qx2 + rx = s, and 'Falsely' implying s as the value of x (Actually, I consider this change as 'False' and call the new variable formed as 'False x', however, I use s instead here)

qx2+rx = s...Making S = x (Yes, I know there is a change in the variable, that is what I find interesting)

qS2+rS = S...Deviding S out then leaves qS + r = 1.

qS = 1 - r, then divide q out.

Thus S is the 'False' x.

(Which is the reason that I started using the capital letter S instead of the lowercase s when I was expressing that in the first post. Perhaps I should have mentioned that...)

Then using the 'False' x in the equation

(FALSE X) - (qx2 + 1)/q = x1
 

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