How are x, y, and z related in their sequences?

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Discussion Overview

The discussion revolves around the relationships between three sequences represented by variables x, y, and z. Participants explore how to derive a formula for z in terms of x and y, as well as identify the nth term for each sequence. The scope includes mathematical reasoning and exploration of patterns in sequences.

Discussion Character

  • Exploratory, Mathematical reasoning, Debate/contested

Main Points Raised

  • One participant presents the sequences for x, y, and z and expresses uncertainty about how to connect them.
  • Another participant proposes specific nth term formulas for each sequence: a(x) = 3n, b(y) = 30 - 2n, and c(z) = 11 - 0.5(n), and attempts to derive a relationship for z in terms of x and y.
  • A different participant suggests an alternative relationship for z, stating that z(x,y) = y/4 + 7/2 is also a valid solution.
  • Another participant references a solution from their book, stating that z = (1/2)(52 - x - y) is the correct answer for part (a).

Areas of Agreement / Disagreement

Participants do not reach a consensus on the relationship between x, y, and z, as multiple competing formulas are proposed, and different interpretations of the sequences are presented.

Contextual Notes

Some participants' formulas may depend on specific interpretations of the sequences or assumptions not explicitly stated. The derivation steps for the relationships are not fully resolved, leaving room for ambiguity.

Who May Find This Useful

Readers interested in mathematical sequences, pattern recognition, and deriving relationships between variables may find this discussion relevant.

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The lists below show the relationship between value of x, y & z.
List A, x: 3, 6, 9, 12, 15,...
List B, y: 28, 26, 24, 22, 20,...
List C, z: 10.5, 10, 9.5, 9, 8.5,...
Find
a) a fomula for z in terms of x and y,
b) the nterm of each sequence.

I can see the pattern in A, B & C but i just am not sure how to connect them.
 
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the nth term for each is givn below:
a(x): 3n
b(y): 30-2n
c(z): 11-0.5(n)

so...z = 11-0.5(n) = (22-n)/2 = (22-4n+3n)/2 = (22-4n +x)/2 = (8+22-2n-2n+x-8)/2
= (30-2n-2n+x-8)/2 = (y+x-2n-8)/2 = y/2 + x/2 - n -4 = z
 
There are many possible solutions.

For example z(x,y) = y/4 + 7/2 will also work just fine.
 
Thanks guys. For (a), my book said that the answer is [tex]z = \frac{1}{2}(52-x-y)[/tex]
 

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