Cory Taylor
2003-05-21 04:29:13 |
sequences
A question I have that I need answered for one of my pending problems.
Is there a difference (mathematically) between a sequence of numbers and a patterned set of numbers? For example, if the answer is no (no difference), then one could extend this meaning a create a "series" of letters, for arguments sake lets say hbtyhbtyhbhbhbty where this "sequence" is formed from the first letter of the words in the song "happy birthday". I was under the impression that a sequence relied upon some mathematical or computational "rule" to progress from one term to the next, while a patterned set of numbers were simply a group of numbers in which the order they are presented contains some significance.
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friedlinguini
2003-05-21 07:20:29 |
Re: sequences
A sequence is an ordered, um, sequence of numbers. The numbers don't have to be unique, and there doesn't have to be a specific rule as long as the sequence is well-defined.
A set is not ordered and all elements are assumed to be unique.
For the sake of completeness, a series is defined as the summation of all numbers in a sequence. |
Cory Taylor
2003-05-21 08:36:56 |
Re: sequences
ok then, 5,8,2,3,5,8,2,3,5,8,5,8,5,8,2,3 would be a sequence because it is the number of letters in the word to the happy birthday song, correct?
Can you expand this to using letters as in my first post? |
Alan
2003-05-21 10:13:12 |
Re: sequences
Well you could call it a sequence but to be a sequence submitted on this site (With that answer) I would have to say that it is definetely not a good one. Now if it is based off of a scientific or mathematical sequence, then it should probably be fine. |
Greg
2003-10-08 18:01:06 |
Re: sequences
Just another note...
You mentioned "I was under the impression that a sequence relied upon some mathematical or computational "rule" to progress from one term to the next"
There are certain TYPES of sequences that do rely on a computational rule. The two most basic ones are
Arithmetic Sequence {10,15,20,25,30,35} (add the same thing each time)
Geometric Sequence {10,20,40,80,160,320}(multiply by the same thing each time)
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alex epson
2003-11-16 09:12:58 |
Re: sequences
I need to know the anser to the following sequence - anyone help?
17 _ _ _ 67 87
alexepson@hotmail.com |
Victor Zapana
2003-11-16 12:55:29 |
Re: sequences
first, its bad to post problems on forums. :-<
second, not enuf info to get an answer of that sequence. |
Gamer
2003-11-16 14:25:30 |
Re: sequences
Yes, just say "I have a sequence to solve" and then put your e-mail if you want ;)
This could be written as a bunch of formulas, even as a quadratic function (like (3(term^2))/2 (7(term))/2 + 24/2)) |
Victor Zapana
2003-11-16 16:36:03 |
Re: sequences
woah Gamer howd u get that quadratic function out that sequence? dang |
Sam
2003-11-16 20:07:59 |
Re: sequences
Easy, he just closed his eyes and visualized the graph of, um, that long equation. For fun he then multiplied it by 1/pi and created some beautiful images with the interference patterns created by the two graphs, but couldn't show them 'cause his mental printer was out of blue ink. Oh well. |
Gamer
2003-11-16 20:20:12 |
Re: sequences
Well, I do that sometimes, but for this particular one I was lazy and used quadratic regression. You can do this by setting up a system of equations, and then solving them by lots of "linear" combination, or by setting up inverse matrices. I am sure the smarties of this forum know plenty of other ways I don't :) |
Tristan
2003-11-16 20:49:30 |
Re: sequences
Really? I'd like to hear them. My self-taught methods don't work very well there. And this is the reference forum. How fitting. |
drew
2003-11-23 13:30:58 |
Re: sequences
i dont know about any of you but when i try gamers function it does not work???
help? |
Gamer
2003-11-23 14:54:40 |
Re: sequences
1 3/2 7/2 24/2 17
2 __
3 __
4 __
5 75/2 35/2 24/2 67
6 108/2 42/2 24/2 87
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drew
2003-11-23 18:11:21 |
Re: sequences
this is not self explanetory
please explain
how do you get 87 from 67 |
Gamer
2003-11-23 18:46:01 |
Re: sequences
If it doesn't go down, maybe you could try the only other option and go across! Surely you have read my formula for the sequence or you couldn't be confused about that! You also must have read the 17,?,?,?,67,87 sequence or you couldn't be confused about that!
I am just showing that it DOES work, even though you said it didn't :)
The term numbers are on the left, each part is in the middle, and their sum are on the right. |
SilverKnight
2003-11-23 19:00:01 |
Re: sequences
All, in an effort to put this to rest... let me simply restate what Gamer has said, perhaps in a more easy to read format:
F(x) = 0.5 * (3x² + 7x + 24)
F(1) = 17
F(2) = 25
F(3) = 36
F(4) = 50
F(5) = 67
F(6) = 87
- SK |
drew
2003-11-23 22:31:36 |
Re: sequences
thanx !SilverKnight! !you! helped alot.
lol |
