# Talk:Geometric sequence/Draft

## Cannot resist

The term still reminds me of the order in which students entered the room for geometry class; I was generally last. --Howard C. Berkowitz 21:44, 9 January 2010 (UTC)

## What about zero?

It is unclear for now, whether the following sequences are geometric or not:

Boris Tsirelson 10:10, 10 May 2010 (UTC)

- Right. But what is meant by 0,0,1 ? --Peter Schmitt 16:52, 11 May 2010 (UTC)
- Just a finite sequence, of length 3, whose first element is 0, second 0, and third 1. (You may think of a possible definition , but I did not say I want it to be in the article; I stay neutral; I only want
*some*definition; and in fact, I feel already satisfied.) Boris Tsirelson 17:34, 11 May 2010 (UTC)- I see. I think it is best to stay with the "standard" (naive) definition here. That is why I did not change the lead, but only added a remark to the formal section. --Peter Schmitt 17:39, 11 May 2010 (UTC)

- Just a finite sequence, of length 3, whose first element is 0, second 0, and third 1. (You may think of a possible definition , but I did not say I want it to be in the article; I stay neutral; I only want

- Right. But what is meant by 0,0,1 ? --Peter Schmitt 16:52, 11 May 2010 (UTC)

## What about q?

"...is called geometric sequence if

for all indices *i*." — I'd add, "and some number *q* (not dependent on *i*)." Boris Tsirelson 10:16, 10 May 2010 (UTC)

- Right. Done. --Peter Schmitt 16:53, 11 May 2010 (UTC)

## More examples

An example of an infinite increasing sequence could be added. Also a constant sequence. Boris Tsirelson 10:20, 10 May 2010 (UTC)

- I have added 3 more ( and 0,0,0 ). --Peter Schmitt 16:54, 11 May 2010 (UTC)

- Nice. Boris Tsirelson 17:35, 11 May 2010 (UTC)

## Dividing by zero

If *q* is permitted to be 1 then the formula for the finite sum needs a reservation. Boris Tsirelson 15:05, 12 May 2010 (UTC)

- Indeed. But not only since the last corrections -- q=1 was never excluded. It seems we both have overlooked it. But I have written it (blushing). --Peter Schmitt 15:55, 12 May 2010 (UTC)

## For non-experts, article needs **many** more examples

It seems to me that, for non-experts, Geometric sequence needs **many** more examples, perhaps duplicate/triplicate examples in some cases. To make it more of a teaching tool for high-schoolers, undergraduates, other groups.

Why sequence called 'geometric'?

Would note vote against approving as is, but would hope for re-approval soon after. Anthony.Sebastian 02:43, 14 May 2010 (UTC)

- 1. Sorry, I do not understand what kind of examples do you mean. Would you please explain? And what do you mean by duplicate?
- 2. I guess, what you really want to see here is a "Tutorial" subpage. But this could wait for version 2. Boris Tsirelson 04:47, 14 May 2010 (UTC)

- Sebastian, the name "geometrical" almost certainly comes from the geometrical interpretation of "proportional" (similar figures), but to include this guess would be hasty. A historical note -- either here or in a separate article -- would be nice to have, but I could not provide it without some thorough research.
- As for more examples: What would they add? I agree that a main page should be as accessible as its topic allows. But an encyclopedia is not a teaching tool -- it is a handbook that should make it easy to find information. Thus it should tell its "story" with as many words as needed, but not with more. (I also confess that I would not know what to do in a Tutorial, either. The only topic I can think of are financial examples, but these would better fit to a page on interest.) --Peter Schmitt 15:14, 14 May 2010 (UTC)

- Not a big deal for me. I'm pretty much of a math dummy. I'll give the article more concerted attention. Anthony.Sebastian 04:16, 16 May 2010 (UTC)

## Approved Version 1

Congratulations again to the Mathematics Workgroup! Not an easy task. Good job! D. Matt Innis 21:59, 14 May 2010 (UTC)