My Math Forum  

Go Back   My Math Forum > High School Math Forum > Algebra

Algebra Pre-Algebra and Basic Algebra Math Forum


Thanks Tree2Thanks
Reply
 
LinkBack Thread Tools Display Modes
April 20th, 2017, 09:35 AM   #11
Global Moderator
 
greg1313's Avatar
 
Joined: Oct 2008
From: London, Ontario, Canada - The Forest City

Posts: 7,488
Thanks: 887

Math Focus: Elementary mathematics and beyond
What kind of instrument are you building?
greg1313 is offline  
 
April 20th, 2017, 10:58 AM   #12
Newbie
 
Joined: Apr 2017
From: Seattle

Posts: 14
Thanks: 1

Quote:
Originally Posted by ronmryd View Post
It's for a harp, not a fretted instrument.
Been being built for hundreds of years without my interference. But I want precision!

Nice with the Roll The Bones avatar BTW.
Thanks from greg1313
ronmryd is offline  
April 20th, 2017, 10:34 PM   #13
Senior Member
 
Joined: Feb 2016
From: Australia

Posts: 1,167
Thanks: 383

Math Focus: Yet to find out.
Quote:
Originally Posted by ronmryd View Post
It's for a harp, not a fretted instrument. Thanks though.
I don't understand. Fretted or not, you essentially want a line divided into 33 sections, with each section getting smaller and smaller as you progress away from one end (or bigger and bigger from the other end). That to me is the same thing.

The website allows you to put your own scaling length in, and the number of frets, or in your case, 33.
Joppy is offline  
April 21st, 2017, 05:34 AM   #14
Newbie
 
Joined: Apr 2017
From: Seattle

Posts: 14
Thanks: 1

I tried their calculator and if only I could set the first and last segments lengths to what I need them to be I would be all set. I can make an excel spreadsheet spit out 35 declinating numbers starting at 1.18 but not with the last one being .88
If no one has a ready solution could anyone point me in a direction to explore instead? Some keywords for a certain type of math discipline to explore? If it's not algebra then perhaps a different sub forum would be appropriate.

If it's unsolvable do I qualify for some million dollar math x-prize?

Thanks again.
ronmryd is offline  
April 21st, 2017, 07:39 AM   #15
Newbie
 
Joined: Apr 2017
From: Seattle

Posts: 14
Thanks: 1

What about a divergent series (not by Veronica Roth) in Calculus? Trying to solve it with triangular numbers doesn't work for this.
ronmryd is offline  
April 21st, 2017, 09:00 AM   #16
Math Team
 
Joined: Oct 2011
From: Ottawa Ontario, Canada

Posts: 9,415
Thanks: 638

Well, I simply can't see why you don't
use ye olde geometric series formula.

With 1st = 118 and 35th = 88, then:
common ratio = r = .991409236551....

And the result is:
1: 118.000
2: 116.986
3: 115.981
4: 114.985
...
33: 89.532
34: 88.763
35: 88.000
Denis is offline  
April 21st, 2017, 09:52 AM   #17
Newbie
 
Joined: Apr 2017
From: Seattle

Posts: 14
Thanks: 1

Denis - A quick question:
Does the sum of the results add up to 33.3? If so then I am forever in your debt and all the other math peoples are shamed!
ronmryd is offline  
April 21st, 2017, 10:51 AM   #18
Math Team
 
Joined: Oct 2011
From: Ottawa Ontario, Canada

Posts: 9,415
Thanks: 638

Quote:
Originally Posted by ronmryd View Post
Denis - A quick question:
Does the sum of the results add up to 33.3? If so then I am forever in your debt and all the other math peoples are shamed!
Huh? The "results" bring 118 down to 88, so add up to 30.
No matter how exotic the calculations are, 118-88 = 30.
Perhaps someone else here will "see" whadda heck you're
doing...so I remain shamed...
Denis is offline  
April 21st, 2017, 11:19 AM   #19
Newbie
 
Joined: Apr 2017
From: Seattle

Posts: 14
Thanks: 1


I didn't mean to imply anything rude!
When I use the geometric sequence with common ratio=.991409236551 and first=1.18 the total sum of the first 35 terms comes out to 35.801
To use the geometric sequence as a solution I would need to be able to the sum, the first first term, the 35th term, and the number of terms. I don't think there is a way to algebra-cadabra the geometric sequence equation so I can input my requirements and have it work.
I apologize to everyone if I haven't been clear in my requirements for this project. I don't know all of the correct keywords of math-ese to explain myself I guess. Until some mentions an idea like "geometric sequence" then I can go look it up and explore it further.
Perhaps it's just me but I intuitively feel like there is a simple solution that I just don't have the tools for. I can hunt and peck a solution in the CAD program but that doesn't help me next time or allow me to easily adjust the design if one of my constraints changes.

Last edited by ronmryd; April 21st, 2017 at 11:22 AM.
ronmryd is offline  
April 21st, 2017, 01:10 PM   #20
Math Team
 
Joined: Oct 2011
From: Ottawa Ontario, Canada

Posts: 9,415
Thanks: 638

Yes, they do add up to ~35.801

Seems like what you're after is something like
2+3=5, but you want 2+3=4.9, and need
a way to change 3 to 2.9 (35.801 to 33.3).
Denis is offline  
Reply

  My Math Forum > High School Math Forum > Algebra

Tags
dividing, line, segments, unequal



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
I need help dividing a line into unequal segments! ronmryd New Users 0 April 19th, 2017 01:11 PM
Calculating the line integral of a curve given line segments nomad609 Calculus 0 October 23rd, 2016 11:39 AM
Geometry piecewise line segments master555 Applied Math 0 December 2nd, 2011 06:56 PM
Line segments-distance andoxx Algebra 7 February 8th, 2011 09:09 PM
Overlap of line segments Cheesy74 Algebra 4 November 17th, 2009 06:23 AM





Copyright © 2017 My Math Forum. All rights reserved.